The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9a664971569daf68254928149f580b4f5856d274 Mon Sep 17 00:00:00 2001
From: ethanwu <ethanwu(a)synology.com>
Date: Tue, 1 Dec 2020 17:25:12 +0800
Subject: [PATCH] btrfs: correctly calculate item size used when item key
collision happens
Item key collision is allowed for some item types, like dir item and
inode refs, but the overall item size is limited by the nodesize.
item size(ins_len) passed from btrfs_insert_empty_items to
btrfs_search_slot already contains size of btrfs_item.
When btrfs_search_slot reaches leaf, we'll see if we need to split leaf.
The check incorrectly reports that split leaf is required, because
it treats the space required by the newly inserted item as
btrfs_item + item data. But in item key collision case, only item data
is actually needed, the newly inserted item could merge into the existing
one. No new btrfs_item will be inserted.
And split_leaf return EOVERFLOW from following code:
if (extend && data_size + btrfs_item_size_nr(l, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info))
return -EOVERFLOW;
In most cases, when callers receive EOVERFLOW, they either return
this error or handle in different ways. For example, in normal dir item
creation the userspace will get errno EOVERFLOW; in inode ref case
INODE_EXTREF is used instead.
However, this is not the case for rename. To avoid the unrecoverable
situation in rename, btrfs_check_dir_item_collision is called in
early phase of rename. In this function, when item key collision is
detected leaf space is checked:
data_size = sizeof(*di) + name_len;
if (data_size + btrfs_item_size_nr(leaf, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info))
the sizeof(struct btrfs_item) + btrfs_item_size_nr(leaf, slot) here
refers to existing item size, the condition here correctly calculates
the needed size for collision case rather than the wrong case above.
The consequence of inconsistent condition check between
btrfs_check_dir_item_collision and btrfs_search_slot when item key
collision happens is that we might pass check here but fail
later at btrfs_search_slot. Rename fails and volume is forced readonly
[436149.586170] ------------[ cut here ]------------
[436149.586173] BTRFS: Transaction aborted (error -75)
[436149.586196] WARNING: CPU: 0 PID: 16733 at fs/btrfs/inode.c:9870 btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586227] CPU: 0 PID: 16733 Comm: python Tainted: G D 4.18.0-rc5+ #1
[436149.586228] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
[436149.586238] RIP: 0010:btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586254] RSP: 0018:ffffa327043a7ce0 EFLAGS: 00010286
[436149.586255] RAX: 0000000000000000 RBX: ffff8d8a17d13340 RCX: 0000000000000006
[436149.586256] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8d8a7fc164b0
[436149.586257] RBP: ffffa327043a7da0 R08: 0000000000000560 R09: 7265282064657472
[436149.586258] R10: 0000000000000000 R11: 6361736e61725420 R12: ffff8d8a0d4c8b08
[436149.586258] R13: ffff8d8a17d13340 R14: ffff8d8a33e0a540 R15: 00000000000001fe
[436149.586260] FS: 00007fa313933740(0000) GS:ffff8d8a7fc00000(0000) knlGS:0000000000000000
[436149.586261] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[436149.586262] CR2: 000055d8d9c9a720 CR3: 000000007aae0003 CR4: 00000000003606f0
[436149.586295] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[436149.586296] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[436149.586296] Call Trace:
[436149.586311] vfs_rename+0x383/0x920
[436149.586313] ? vfs_rename+0x383/0x920
[436149.586315] do_renameat2+0x4ca/0x590
[436149.586317] __x64_sys_rename+0x20/0x30
[436149.586324] do_syscall_64+0x5a/0x120
[436149.586330] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[436149.586332] RIP: 0033:0x7fa3133b1d37
[436149.586348] RSP: 002b:00007fffd3e43908 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
[436149.586349] RAX: ffffffffffffffda RBX: 00007fa3133b1d30 RCX: 00007fa3133b1d37
[436149.586350] RDX: 000055d8da06b5e0 RSI: 000055d8da225d60 RDI: 000055d8da2c4da0
[436149.586351] RBP: 000055d8da2252f0 R08: 00007fa313782000 R09: 00000000000177e0
[436149.586351] R10: 000055d8da010680 R11: 0000000000000246 R12: 00007fa313840b00
Thanks to Hans van Kranenburg for information about crc32 hash collision
tools, I was able to reproduce the dir item collision with following
python script.
https://github.com/wutzuchieh/misc_tools/blob/master/crc32_forge.py Run
it under a btrfs volume will trigger the abort transaction. It simply
creates files and rename them to forged names that leads to
hash collision.
There are two ways to fix this. One is to simply revert the patch
878f2d2cb355 ("Btrfs: fix max dir item size calculation") to make the
condition consistent although that patch is correct about the size.
The other way is to handle the leaf space check correctly when
collision happens. I prefer the second one since it correct leaf
space check in collision case. This fix will not account
sizeof(struct btrfs_item) when the item already exists.
There are two places where ins_len doesn't contain
sizeof(struct btrfs_item), however.
1. extent-tree.c: lookup_inline_extent_backref
2. file-item.c: btrfs_csum_file_blocks
to make the logic of btrfs_search_slot more clear, we add a flag
search_for_extension in btrfs_path.
This flag indicates that ins_len passed to btrfs_search_slot doesn't
contain sizeof(struct btrfs_item). When key exists, btrfs_search_slot
will use the actual size needed to calculate the required leaf space.
CC: stable(a)vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: ethanwu <ethanwu(a)synology.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 07810891e204..cc89b63d65a4 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2555,8 +2555,14 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root,
* @p: Holds all btree nodes along the search path
* @root: The root node of the tree
* @key: The key we are looking for
- * @ins_len: Indicates purpose of search, for inserts it is 1, for
- * deletions it's -1. 0 for plain searches
+ * @ins_len: Indicates purpose of search:
+ * >0 for inserts it's size of item inserted (*)
+ * <0 for deletions
+ * 0 for plain searches, not modifying the tree
+ *
+ * (*) If size of item inserted doesn't include
+ * sizeof(struct btrfs_item), then p->search_for_extension must
+ * be set.
* @cow: boolean should CoW operations be performed. Must always be 1
* when modifying the tree.
*
@@ -2717,6 +2723,20 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
if (level == 0) {
p->slots[level] = slot;
+ /*
+ * Item key already exists. In this case, if we are
+ * allowed to insert the item (for example, in dir_item
+ * case, item key collision is allowed), it will be
+ * merged with the original item. Only the item size
+ * grows, no new btrfs item will be added. If
+ * search_for_extension is not set, ins_len already
+ * accounts the size btrfs_item, deduct it here so leaf
+ * space check will be correct.
+ */
+ if (ret == 0 && ins_len > 0 && !p->search_for_extension) {
+ ASSERT(ins_len >= sizeof(struct btrfs_item));
+ ins_len -= sizeof(struct btrfs_item);
+ }
if (ins_len > 0 &&
btrfs_leaf_free_space(b) < ins_len) {
if (write_lock_level < 1) {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2674f24cf2e0..3935d297d198 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -368,6 +368,12 @@ struct btrfs_path {
unsigned int search_commit_root:1;
unsigned int need_commit_sem:1;
unsigned int skip_release_on_error:1;
+ /*
+ * Indicate that new item (btrfs_search_slot) is extending already
+ * existing item and ins_len contains only the data size and not item
+ * header (ie. sizeof(struct btrfs_item) is not included).
+ */
+ unsigned int search_for_extension:1;
};
#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
sizeof(struct btrfs_item))
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 56ea380f5a17..d79b8369e6aa 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -844,6 +844,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
want = extent_ref_type(parent, owner);
if (insert) {
extra_size = btrfs_extent_inline_ref_size(want);
+ path->search_for_extension = 1;
path->keep_locks = 1;
} else
extra_size = -1;
@@ -996,6 +997,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
out:
if (insert) {
path->keep_locks = 0;
+ path->search_for_extension = 0;
btrfs_unlock_up_safe(path, 1);
}
return err;
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 1545c22ef280..6ccfc019ad90 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -1016,8 +1016,10 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
}
btrfs_release_path(path);
+ path->search_for_extension = 1;
ret = btrfs_search_slot(trans, root, &file_key, path,
csum_size, 1);
+ path->search_for_extension = 0;
if (ret < 0)
goto out;
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9a664971569daf68254928149f580b4f5856d274 Mon Sep 17 00:00:00 2001
From: ethanwu <ethanwu(a)synology.com>
Date: Tue, 1 Dec 2020 17:25:12 +0800
Subject: [PATCH] btrfs: correctly calculate item size used when item key
collision happens
Item key collision is allowed for some item types, like dir item and
inode refs, but the overall item size is limited by the nodesize.
item size(ins_len) passed from btrfs_insert_empty_items to
btrfs_search_slot already contains size of btrfs_item.
When btrfs_search_slot reaches leaf, we'll see if we need to split leaf.
The check incorrectly reports that split leaf is required, because
it treats the space required by the newly inserted item as
btrfs_item + item data. But in item key collision case, only item data
is actually needed, the newly inserted item could merge into the existing
one. No new btrfs_item will be inserted.
And split_leaf return EOVERFLOW from following code:
if (extend && data_size + btrfs_item_size_nr(l, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info))
return -EOVERFLOW;
In most cases, when callers receive EOVERFLOW, they either return
this error or handle in different ways. For example, in normal dir item
creation the userspace will get errno EOVERFLOW; in inode ref case
INODE_EXTREF is used instead.
However, this is not the case for rename. To avoid the unrecoverable
situation in rename, btrfs_check_dir_item_collision is called in
early phase of rename. In this function, when item key collision is
detected leaf space is checked:
data_size = sizeof(*di) + name_len;
if (data_size + btrfs_item_size_nr(leaf, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info))
the sizeof(struct btrfs_item) + btrfs_item_size_nr(leaf, slot) here
refers to existing item size, the condition here correctly calculates
the needed size for collision case rather than the wrong case above.
The consequence of inconsistent condition check between
btrfs_check_dir_item_collision and btrfs_search_slot when item key
collision happens is that we might pass check here but fail
later at btrfs_search_slot. Rename fails and volume is forced readonly
[436149.586170] ------------[ cut here ]------------
[436149.586173] BTRFS: Transaction aborted (error -75)
[436149.586196] WARNING: CPU: 0 PID: 16733 at fs/btrfs/inode.c:9870 btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586227] CPU: 0 PID: 16733 Comm: python Tainted: G D 4.18.0-rc5+ #1
[436149.586228] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
[436149.586238] RIP: 0010:btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586254] RSP: 0018:ffffa327043a7ce0 EFLAGS: 00010286
[436149.586255] RAX: 0000000000000000 RBX: ffff8d8a17d13340 RCX: 0000000000000006
[436149.586256] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8d8a7fc164b0
[436149.586257] RBP: ffffa327043a7da0 R08: 0000000000000560 R09: 7265282064657472
[436149.586258] R10: 0000000000000000 R11: 6361736e61725420 R12: ffff8d8a0d4c8b08
[436149.586258] R13: ffff8d8a17d13340 R14: ffff8d8a33e0a540 R15: 00000000000001fe
[436149.586260] FS: 00007fa313933740(0000) GS:ffff8d8a7fc00000(0000) knlGS:0000000000000000
[436149.586261] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[436149.586262] CR2: 000055d8d9c9a720 CR3: 000000007aae0003 CR4: 00000000003606f0
[436149.586295] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[436149.586296] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[436149.586296] Call Trace:
[436149.586311] vfs_rename+0x383/0x920
[436149.586313] ? vfs_rename+0x383/0x920
[436149.586315] do_renameat2+0x4ca/0x590
[436149.586317] __x64_sys_rename+0x20/0x30
[436149.586324] do_syscall_64+0x5a/0x120
[436149.586330] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[436149.586332] RIP: 0033:0x7fa3133b1d37
[436149.586348] RSP: 002b:00007fffd3e43908 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
[436149.586349] RAX: ffffffffffffffda RBX: 00007fa3133b1d30 RCX: 00007fa3133b1d37
[436149.586350] RDX: 000055d8da06b5e0 RSI: 000055d8da225d60 RDI: 000055d8da2c4da0
[436149.586351] RBP: 000055d8da2252f0 R08: 00007fa313782000 R09: 00000000000177e0
[436149.586351] R10: 000055d8da010680 R11: 0000000000000246 R12: 00007fa313840b00
Thanks to Hans van Kranenburg for information about crc32 hash collision
tools, I was able to reproduce the dir item collision with following
python script.
https://github.com/wutzuchieh/misc_tools/blob/master/crc32_forge.py Run
it under a btrfs volume will trigger the abort transaction. It simply
creates files and rename them to forged names that leads to
hash collision.
There are two ways to fix this. One is to simply revert the patch
878f2d2cb355 ("Btrfs: fix max dir item size calculation") to make the
condition consistent although that patch is correct about the size.
The other way is to handle the leaf space check correctly when
collision happens. I prefer the second one since it correct leaf
space check in collision case. This fix will not account
sizeof(struct btrfs_item) when the item already exists.
There are two places where ins_len doesn't contain
sizeof(struct btrfs_item), however.
1. extent-tree.c: lookup_inline_extent_backref
2. file-item.c: btrfs_csum_file_blocks
to make the logic of btrfs_search_slot more clear, we add a flag
search_for_extension in btrfs_path.
This flag indicates that ins_len passed to btrfs_search_slot doesn't
contain sizeof(struct btrfs_item). When key exists, btrfs_search_slot
will use the actual size needed to calculate the required leaf space.
CC: stable(a)vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: ethanwu <ethanwu(a)synology.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 07810891e204..cc89b63d65a4 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2555,8 +2555,14 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root,
* @p: Holds all btree nodes along the search path
* @root: The root node of the tree
* @key: The key we are looking for
- * @ins_len: Indicates purpose of search, for inserts it is 1, for
- * deletions it's -1. 0 for plain searches
+ * @ins_len: Indicates purpose of search:
+ * >0 for inserts it's size of item inserted (*)
+ * <0 for deletions
+ * 0 for plain searches, not modifying the tree
+ *
+ * (*) If size of item inserted doesn't include
+ * sizeof(struct btrfs_item), then p->search_for_extension must
+ * be set.
* @cow: boolean should CoW operations be performed. Must always be 1
* when modifying the tree.
*
@@ -2717,6 +2723,20 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
if (level == 0) {
p->slots[level] = slot;
+ /*
+ * Item key already exists. In this case, if we are
+ * allowed to insert the item (for example, in dir_item
+ * case, item key collision is allowed), it will be
+ * merged with the original item. Only the item size
+ * grows, no new btrfs item will be added. If
+ * search_for_extension is not set, ins_len already
+ * accounts the size btrfs_item, deduct it here so leaf
+ * space check will be correct.
+ */
+ if (ret == 0 && ins_len > 0 && !p->search_for_extension) {
+ ASSERT(ins_len >= sizeof(struct btrfs_item));
+ ins_len -= sizeof(struct btrfs_item);
+ }
if (ins_len > 0 &&
btrfs_leaf_free_space(b) < ins_len) {
if (write_lock_level < 1) {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2674f24cf2e0..3935d297d198 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -368,6 +368,12 @@ struct btrfs_path {
unsigned int search_commit_root:1;
unsigned int need_commit_sem:1;
unsigned int skip_release_on_error:1;
+ /*
+ * Indicate that new item (btrfs_search_slot) is extending already
+ * existing item and ins_len contains only the data size and not item
+ * header (ie. sizeof(struct btrfs_item) is not included).
+ */
+ unsigned int search_for_extension:1;
};
#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
sizeof(struct btrfs_item))
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 56ea380f5a17..d79b8369e6aa 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -844,6 +844,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
want = extent_ref_type(parent, owner);
if (insert) {
extra_size = btrfs_extent_inline_ref_size(want);
+ path->search_for_extension = 1;
path->keep_locks = 1;
} else
extra_size = -1;
@@ -996,6 +997,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
out:
if (insert) {
path->keep_locks = 0;
+ path->search_for_extension = 0;
btrfs_unlock_up_safe(path, 1);
}
return err;
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 1545c22ef280..6ccfc019ad90 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -1016,8 +1016,10 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
}
btrfs_release_path(path);
+ path->search_for_extension = 1;
ret = btrfs_search_slot(trans, root, &file_key, path,
csum_size, 1);
+ path->search_for_extension = 0;
if (ret < 0)
goto out;
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9a664971569daf68254928149f580b4f5856d274 Mon Sep 17 00:00:00 2001
From: ethanwu <ethanwu(a)synology.com>
Date: Tue, 1 Dec 2020 17:25:12 +0800
Subject: [PATCH] btrfs: correctly calculate item size used when item key
collision happens
Item key collision is allowed for some item types, like dir item and
inode refs, but the overall item size is limited by the nodesize.
item size(ins_len) passed from btrfs_insert_empty_items to
btrfs_search_slot already contains size of btrfs_item.
When btrfs_search_slot reaches leaf, we'll see if we need to split leaf.
The check incorrectly reports that split leaf is required, because
it treats the space required by the newly inserted item as
btrfs_item + item data. But in item key collision case, only item data
is actually needed, the newly inserted item could merge into the existing
one. No new btrfs_item will be inserted.
And split_leaf return EOVERFLOW from following code:
if (extend && data_size + btrfs_item_size_nr(l, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info))
return -EOVERFLOW;
In most cases, when callers receive EOVERFLOW, they either return
this error or handle in different ways. For example, in normal dir item
creation the userspace will get errno EOVERFLOW; in inode ref case
INODE_EXTREF is used instead.
However, this is not the case for rename. To avoid the unrecoverable
situation in rename, btrfs_check_dir_item_collision is called in
early phase of rename. In this function, when item key collision is
detected leaf space is checked:
data_size = sizeof(*di) + name_len;
if (data_size + btrfs_item_size_nr(leaf, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info))
the sizeof(struct btrfs_item) + btrfs_item_size_nr(leaf, slot) here
refers to existing item size, the condition here correctly calculates
the needed size for collision case rather than the wrong case above.
The consequence of inconsistent condition check between
btrfs_check_dir_item_collision and btrfs_search_slot when item key
collision happens is that we might pass check here but fail
later at btrfs_search_slot. Rename fails and volume is forced readonly
[436149.586170] ------------[ cut here ]------------
[436149.586173] BTRFS: Transaction aborted (error -75)
[436149.586196] WARNING: CPU: 0 PID: 16733 at fs/btrfs/inode.c:9870 btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586227] CPU: 0 PID: 16733 Comm: python Tainted: G D 4.18.0-rc5+ #1
[436149.586228] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
[436149.586238] RIP: 0010:btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586254] RSP: 0018:ffffa327043a7ce0 EFLAGS: 00010286
[436149.586255] RAX: 0000000000000000 RBX: ffff8d8a17d13340 RCX: 0000000000000006
[436149.586256] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8d8a7fc164b0
[436149.586257] RBP: ffffa327043a7da0 R08: 0000000000000560 R09: 7265282064657472
[436149.586258] R10: 0000000000000000 R11: 6361736e61725420 R12: ffff8d8a0d4c8b08
[436149.586258] R13: ffff8d8a17d13340 R14: ffff8d8a33e0a540 R15: 00000000000001fe
[436149.586260] FS: 00007fa313933740(0000) GS:ffff8d8a7fc00000(0000) knlGS:0000000000000000
[436149.586261] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[436149.586262] CR2: 000055d8d9c9a720 CR3: 000000007aae0003 CR4: 00000000003606f0
[436149.586295] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[436149.586296] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[436149.586296] Call Trace:
[436149.586311] vfs_rename+0x383/0x920
[436149.586313] ? vfs_rename+0x383/0x920
[436149.586315] do_renameat2+0x4ca/0x590
[436149.586317] __x64_sys_rename+0x20/0x30
[436149.586324] do_syscall_64+0x5a/0x120
[436149.586330] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[436149.586332] RIP: 0033:0x7fa3133b1d37
[436149.586348] RSP: 002b:00007fffd3e43908 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
[436149.586349] RAX: ffffffffffffffda RBX: 00007fa3133b1d30 RCX: 00007fa3133b1d37
[436149.586350] RDX: 000055d8da06b5e0 RSI: 000055d8da225d60 RDI: 000055d8da2c4da0
[436149.586351] RBP: 000055d8da2252f0 R08: 00007fa313782000 R09: 00000000000177e0
[436149.586351] R10: 000055d8da010680 R11: 0000000000000246 R12: 00007fa313840b00
Thanks to Hans van Kranenburg for information about crc32 hash collision
tools, I was able to reproduce the dir item collision with following
python script.
https://github.com/wutzuchieh/misc_tools/blob/master/crc32_forge.py Run
it under a btrfs volume will trigger the abort transaction. It simply
creates files and rename them to forged names that leads to
hash collision.
There are two ways to fix this. One is to simply revert the patch
878f2d2cb355 ("Btrfs: fix max dir item size calculation") to make the
condition consistent although that patch is correct about the size.
The other way is to handle the leaf space check correctly when
collision happens. I prefer the second one since it correct leaf
space check in collision case. This fix will not account
sizeof(struct btrfs_item) when the item already exists.
There are two places where ins_len doesn't contain
sizeof(struct btrfs_item), however.
1. extent-tree.c: lookup_inline_extent_backref
2. file-item.c: btrfs_csum_file_blocks
to make the logic of btrfs_search_slot more clear, we add a flag
search_for_extension in btrfs_path.
This flag indicates that ins_len passed to btrfs_search_slot doesn't
contain sizeof(struct btrfs_item). When key exists, btrfs_search_slot
will use the actual size needed to calculate the required leaf space.
CC: stable(a)vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: ethanwu <ethanwu(a)synology.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 07810891e204..cc89b63d65a4 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2555,8 +2555,14 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root,
* @p: Holds all btree nodes along the search path
* @root: The root node of the tree
* @key: The key we are looking for
- * @ins_len: Indicates purpose of search, for inserts it is 1, for
- * deletions it's -1. 0 for plain searches
+ * @ins_len: Indicates purpose of search:
+ * >0 for inserts it's size of item inserted (*)
+ * <0 for deletions
+ * 0 for plain searches, not modifying the tree
+ *
+ * (*) If size of item inserted doesn't include
+ * sizeof(struct btrfs_item), then p->search_for_extension must
+ * be set.
* @cow: boolean should CoW operations be performed. Must always be 1
* when modifying the tree.
*
@@ -2717,6 +2723,20 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
if (level == 0) {
p->slots[level] = slot;
+ /*
+ * Item key already exists. In this case, if we are
+ * allowed to insert the item (for example, in dir_item
+ * case, item key collision is allowed), it will be
+ * merged with the original item. Only the item size
+ * grows, no new btrfs item will be added. If
+ * search_for_extension is not set, ins_len already
+ * accounts the size btrfs_item, deduct it here so leaf
+ * space check will be correct.
+ */
+ if (ret == 0 && ins_len > 0 && !p->search_for_extension) {
+ ASSERT(ins_len >= sizeof(struct btrfs_item));
+ ins_len -= sizeof(struct btrfs_item);
+ }
if (ins_len > 0 &&
btrfs_leaf_free_space(b) < ins_len) {
if (write_lock_level < 1) {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2674f24cf2e0..3935d297d198 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -368,6 +368,12 @@ struct btrfs_path {
unsigned int search_commit_root:1;
unsigned int need_commit_sem:1;
unsigned int skip_release_on_error:1;
+ /*
+ * Indicate that new item (btrfs_search_slot) is extending already
+ * existing item and ins_len contains only the data size and not item
+ * header (ie. sizeof(struct btrfs_item) is not included).
+ */
+ unsigned int search_for_extension:1;
};
#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
sizeof(struct btrfs_item))
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 56ea380f5a17..d79b8369e6aa 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -844,6 +844,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
want = extent_ref_type(parent, owner);
if (insert) {
extra_size = btrfs_extent_inline_ref_size(want);
+ path->search_for_extension = 1;
path->keep_locks = 1;
} else
extra_size = -1;
@@ -996,6 +997,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
out:
if (insert) {
path->keep_locks = 0;
+ path->search_for_extension = 0;
btrfs_unlock_up_safe(path, 1);
}
return err;
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 1545c22ef280..6ccfc019ad90 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -1016,8 +1016,10 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
}
btrfs_release_path(path);
+ path->search_for_extension = 1;
ret = btrfs_search_slot(trans, root, &file_key, path,
csum_size, 1);
+ path->search_for_extension = 0;
if (ret < 0)
goto out;
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9a664971569daf68254928149f580b4f5856d274 Mon Sep 17 00:00:00 2001
From: ethanwu <ethanwu(a)synology.com>
Date: Tue, 1 Dec 2020 17:25:12 +0800
Subject: [PATCH] btrfs: correctly calculate item size used when item key
collision happens
Item key collision is allowed for some item types, like dir item and
inode refs, but the overall item size is limited by the nodesize.
item size(ins_len) passed from btrfs_insert_empty_items to
btrfs_search_slot already contains size of btrfs_item.
When btrfs_search_slot reaches leaf, we'll see if we need to split leaf.
The check incorrectly reports that split leaf is required, because
it treats the space required by the newly inserted item as
btrfs_item + item data. But in item key collision case, only item data
is actually needed, the newly inserted item could merge into the existing
one. No new btrfs_item will be inserted.
And split_leaf return EOVERFLOW from following code:
if (extend && data_size + btrfs_item_size_nr(l, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info))
return -EOVERFLOW;
In most cases, when callers receive EOVERFLOW, they either return
this error or handle in different ways. For example, in normal dir item
creation the userspace will get errno EOVERFLOW; in inode ref case
INODE_EXTREF is used instead.
However, this is not the case for rename. To avoid the unrecoverable
situation in rename, btrfs_check_dir_item_collision is called in
early phase of rename. In this function, when item key collision is
detected leaf space is checked:
data_size = sizeof(*di) + name_len;
if (data_size + btrfs_item_size_nr(leaf, slot) +
sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root->fs_info))
the sizeof(struct btrfs_item) + btrfs_item_size_nr(leaf, slot) here
refers to existing item size, the condition here correctly calculates
the needed size for collision case rather than the wrong case above.
The consequence of inconsistent condition check between
btrfs_check_dir_item_collision and btrfs_search_slot when item key
collision happens is that we might pass check here but fail
later at btrfs_search_slot. Rename fails and volume is forced readonly
[436149.586170] ------------[ cut here ]------------
[436149.586173] BTRFS: Transaction aborted (error -75)
[436149.586196] WARNING: CPU: 0 PID: 16733 at fs/btrfs/inode.c:9870 btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586227] CPU: 0 PID: 16733 Comm: python Tainted: G D 4.18.0-rc5+ #1
[436149.586228] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
[436149.586238] RIP: 0010:btrfs_rename2+0x1938/0x1b70 [btrfs]
[436149.586254] RSP: 0018:ffffa327043a7ce0 EFLAGS: 00010286
[436149.586255] RAX: 0000000000000000 RBX: ffff8d8a17d13340 RCX: 0000000000000006
[436149.586256] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8d8a7fc164b0
[436149.586257] RBP: ffffa327043a7da0 R08: 0000000000000560 R09: 7265282064657472
[436149.586258] R10: 0000000000000000 R11: 6361736e61725420 R12: ffff8d8a0d4c8b08
[436149.586258] R13: ffff8d8a17d13340 R14: ffff8d8a33e0a540 R15: 00000000000001fe
[436149.586260] FS: 00007fa313933740(0000) GS:ffff8d8a7fc00000(0000) knlGS:0000000000000000
[436149.586261] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[436149.586262] CR2: 000055d8d9c9a720 CR3: 000000007aae0003 CR4: 00000000003606f0
[436149.586295] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[436149.586296] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[436149.586296] Call Trace:
[436149.586311] vfs_rename+0x383/0x920
[436149.586313] ? vfs_rename+0x383/0x920
[436149.586315] do_renameat2+0x4ca/0x590
[436149.586317] __x64_sys_rename+0x20/0x30
[436149.586324] do_syscall_64+0x5a/0x120
[436149.586330] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[436149.586332] RIP: 0033:0x7fa3133b1d37
[436149.586348] RSP: 002b:00007fffd3e43908 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
[436149.586349] RAX: ffffffffffffffda RBX: 00007fa3133b1d30 RCX: 00007fa3133b1d37
[436149.586350] RDX: 000055d8da06b5e0 RSI: 000055d8da225d60 RDI: 000055d8da2c4da0
[436149.586351] RBP: 000055d8da2252f0 R08: 00007fa313782000 R09: 00000000000177e0
[436149.586351] R10: 000055d8da010680 R11: 0000000000000246 R12: 00007fa313840b00
Thanks to Hans van Kranenburg for information about crc32 hash collision
tools, I was able to reproduce the dir item collision with following
python script.
https://github.com/wutzuchieh/misc_tools/blob/master/crc32_forge.py Run
it under a btrfs volume will trigger the abort transaction. It simply
creates files and rename them to forged names that leads to
hash collision.
There are two ways to fix this. One is to simply revert the patch
878f2d2cb355 ("Btrfs: fix max dir item size calculation") to make the
condition consistent although that patch is correct about the size.
The other way is to handle the leaf space check correctly when
collision happens. I prefer the second one since it correct leaf
space check in collision case. This fix will not account
sizeof(struct btrfs_item) when the item already exists.
There are two places where ins_len doesn't contain
sizeof(struct btrfs_item), however.
1. extent-tree.c: lookup_inline_extent_backref
2. file-item.c: btrfs_csum_file_blocks
to make the logic of btrfs_search_slot more clear, we add a flag
search_for_extension in btrfs_path.
This flag indicates that ins_len passed to btrfs_search_slot doesn't
contain sizeof(struct btrfs_item). When key exists, btrfs_search_slot
will use the actual size needed to calculate the required leaf space.
CC: stable(a)vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: ethanwu <ethanwu(a)synology.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 07810891e204..cc89b63d65a4 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2555,8 +2555,14 @@ static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root,
* @p: Holds all btree nodes along the search path
* @root: The root node of the tree
* @key: The key we are looking for
- * @ins_len: Indicates purpose of search, for inserts it is 1, for
- * deletions it's -1. 0 for plain searches
+ * @ins_len: Indicates purpose of search:
+ * >0 for inserts it's size of item inserted (*)
+ * <0 for deletions
+ * 0 for plain searches, not modifying the tree
+ *
+ * (*) If size of item inserted doesn't include
+ * sizeof(struct btrfs_item), then p->search_for_extension must
+ * be set.
* @cow: boolean should CoW operations be performed. Must always be 1
* when modifying the tree.
*
@@ -2717,6 +2723,20 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
if (level == 0) {
p->slots[level] = slot;
+ /*
+ * Item key already exists. In this case, if we are
+ * allowed to insert the item (for example, in dir_item
+ * case, item key collision is allowed), it will be
+ * merged with the original item. Only the item size
+ * grows, no new btrfs item will be added. If
+ * search_for_extension is not set, ins_len already
+ * accounts the size btrfs_item, deduct it here so leaf
+ * space check will be correct.
+ */
+ if (ret == 0 && ins_len > 0 && !p->search_for_extension) {
+ ASSERT(ins_len >= sizeof(struct btrfs_item));
+ ins_len -= sizeof(struct btrfs_item);
+ }
if (ins_len > 0 &&
btrfs_leaf_free_space(b) < ins_len) {
if (write_lock_level < 1) {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2674f24cf2e0..3935d297d198 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -368,6 +368,12 @@ struct btrfs_path {
unsigned int search_commit_root:1;
unsigned int need_commit_sem:1;
unsigned int skip_release_on_error:1;
+ /*
+ * Indicate that new item (btrfs_search_slot) is extending already
+ * existing item and ins_len contains only the data size and not item
+ * header (ie. sizeof(struct btrfs_item) is not included).
+ */
+ unsigned int search_for_extension:1;
};
#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r->fs_info) >> 4) - \
sizeof(struct btrfs_item))
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 56ea380f5a17..d79b8369e6aa 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -844,6 +844,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
want = extent_ref_type(parent, owner);
if (insert) {
extra_size = btrfs_extent_inline_ref_size(want);
+ path->search_for_extension = 1;
path->keep_locks = 1;
} else
extra_size = -1;
@@ -996,6 +997,7 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
out:
if (insert) {
path->keep_locks = 0;
+ path->search_for_extension = 0;
btrfs_unlock_up_safe(path, 1);
}
return err;
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 1545c22ef280..6ccfc019ad90 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -1016,8 +1016,10 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
}
btrfs_release_path(path);
+ path->search_for_extension = 1;
ret = btrfs_search_slot(trans, root, &file_key, path,
csum_size, 1);
+ path->search_for_extension = 0;
if (ret < 0)
goto out;
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9ad9f45b3b91162b33abfe175ae75ab65718dbf5 Mon Sep 17 00:00:00 2001
From: Liu Yi L <yi.l.liu(a)intel.com>
Date: Thu, 7 Jan 2021 00:03:55 +0800
Subject: [PATCH] iommu/vt-d: Move intel_iommu info from struct intel_svm to
struct intel_svm_dev
'struct intel_svm' is shared by all devices bound to a give process,
but records only a single pointer to a 'struct intel_iommu'. Consequently,
cache invalidations may only be applied to a single DMAR unit, and are
erroneously skipped for the other devices.
In preparation for fixing this, rework the structures so that the iommu
pointer resides in 'struct intel_svm_dev', allowing 'struct intel_svm'
to track them in its device list.
Fixes: 1c4f88b7f1f9 ("iommu/vt-d: Shared virtual address in scalable mode")
Cc: Lu Baolu <baolu.lu(a)linux.intel.com>
Cc: Jacob Pan <jacob.jun.pan(a)linux.intel.com>
Cc: Raj Ashok <ashok.raj(a)intel.com>
Cc: David Woodhouse <dwmw2(a)infradead.org>
Reported-by: Guo Kaijie <Kaijie.Guo(a)intel.com>
Reported-by: Xin Zeng <xin.zeng(a)intel.com>
Signed-off-by: Guo Kaijie <Kaijie.Guo(a)intel.com>
Signed-off-by: Xin Zeng <xin.zeng(a)intel.com>
Signed-off-by: Liu Yi L <yi.l.liu(a)intel.com>
Tested-by: Guo Kaijie <Kaijie.Guo(a)intel.com>
Cc: stable(a)vger.kernel.org # v5.0+
Acked-by: Lu Baolu <baolu.lu(a)linux.intel.com>
Link: https://lore.kernel.org/r/1609949037-25291-2-git-send-email-yi.l.liu@intel.…
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 9bcedd360235..790ef3497e7e 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -142,7 +142,7 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d
}
desc.qw2 = 0;
desc.qw3 = 0;
- qi_submit_sync(svm->iommu, &desc, 1, 0);
+ qi_submit_sync(sdev->iommu, &desc, 1, 0);
if (sdev->dev_iotlb) {
desc.qw0 = QI_DEV_EIOTLB_PASID(svm->pasid) |
@@ -166,7 +166,7 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d
}
desc.qw2 = 0;
desc.qw3 = 0;
- qi_submit_sync(svm->iommu, &desc, 1, 0);
+ qi_submit_sync(sdev->iommu, &desc, 1, 0);
}
}
@@ -211,7 +211,7 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
*/
rcu_read_lock();
list_for_each_entry_rcu(sdev, &svm->devs, list)
- intel_pasid_tear_down_entry(svm->iommu, sdev->dev,
+ intel_pasid_tear_down_entry(sdev->iommu, sdev->dev,
svm->pasid, true);
rcu_read_unlock();
@@ -364,6 +364,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
}
sdev->dev = dev;
sdev->sid = PCI_DEVID(info->bus, info->devfn);
+ sdev->iommu = iommu;
/* Only count users if device has aux domains */
if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
@@ -548,6 +549,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
goto out;
}
sdev->dev = dev;
+ sdev->iommu = iommu;
ret = intel_iommu_enable_pasid(iommu, dev);
if (ret) {
@@ -577,7 +579,6 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
kfree(sdev);
goto out;
}
- svm->iommu = iommu;
if (pasid_max > intel_pasid_max_id)
pasid_max = intel_pasid_max_id;
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index d956987ed032..94522685a0d9 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -758,6 +758,7 @@ struct intel_svm_dev {
struct list_head list;
struct rcu_head rcu;
struct device *dev;
+ struct intel_iommu *iommu;
struct svm_dev_ops *ops;
struct iommu_sva sva;
u32 pasid;
@@ -771,7 +772,6 @@ struct intel_svm {
struct mmu_notifier notifier;
struct mm_struct *mm;
- struct intel_iommu *iommu;
unsigned int flags;
u32 pasid;
int gpasid; /* In case that guest PASID is different from host PASID */
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From d16baa3f1453c14d680c5fee01cd122a22d0e0ce Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj(a)kernel.org>
Date: Tue, 5 Jan 2021 12:37:23 -0500
Subject: [PATCH] blk-iocost: fix NULL iocg deref from racing against
initialization
When initializing iocost for a queue, its rqos should be registered before
the blkcg policy is activated to allow policy data initiailization to lookup
the associated ioc. This unfortunately means that the rqos methods can be
called on bios before iocgs are attached to all existing blkgs.
While the race is theoretically possible on ioc_rqos_throttle(), it mostly
happened in ioc_rqos_merge() due to the difference in how they lookup ioc.
The former determines it from the passed in @rqos and then bails before
dereferencing iocg if the looked up ioc is disabled, which most likely is
the case if initialization is still in progress. The latter looked up ioc by
dereferencing the possibly NULL iocg making it a lot more prone to actually
triggering the bug.
* Make ioc_rqos_merge() use the same method as ioc_rqos_throttle() to look
up ioc for consistency.
* Make ioc_rqos_throttle() and ioc_rqos_merge() test for NULL iocg before
dereferencing it.
* Explain the danger of NULL iocgs in blk_iocost_init().
Signed-off-by: Tejun Heo <tj(a)kernel.org>
Reported-by: Jonathan Lemon <bsd(a)fb.com>
Cc: stable(a)vger.kernel.org # v5.4+
Signed-off-by: Jens Axboe <axboe(a)kernel.dk>
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index ac6078a34939..98d656bdb42b 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2551,8 +2551,8 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio)
bool use_debt, ioc_locked;
unsigned long flags;
- /* bypass IOs if disabled or for root cgroup */
- if (!ioc->enabled || !iocg->level)
+ /* bypass IOs if disabled, still initializing, or for root cgroup */
+ if (!ioc->enabled || !iocg || !iocg->level)
return;
/* calculate the absolute vtime cost */
@@ -2679,14 +2679,14 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq,
struct bio *bio)
{
struct ioc_gq *iocg = blkg_to_iocg(bio->bi_blkg);
- struct ioc *ioc = iocg->ioc;
+ struct ioc *ioc = rqos_to_ioc(rqos);
sector_t bio_end = bio_end_sector(bio);
struct ioc_now now;
u64 vtime, abs_cost, cost;
unsigned long flags;
- /* bypass if disabled or for root cgroup */
- if (!ioc->enabled || !iocg->level)
+ /* bypass if disabled, still initializing, or for root cgroup */
+ if (!ioc->enabled || !iocg || !iocg->level)
return;
abs_cost = calc_vtime_cost(bio, iocg, true);
@@ -2863,6 +2863,12 @@ static int blk_iocost_init(struct request_queue *q)
ioc_refresh_params(ioc, true);
spin_unlock_irq(&ioc->lock);
+ /*
+ * rqos must be added before activation to allow iocg_pd_init() to
+ * lookup the ioc from q. This means that the rqos methods may get
+ * called before policy activation completion, can't assume that the
+ * target bio has an iocg associated and need to test for NULL iocg.
+ */
rq_qos_add(q, rqos);
ret = blkcg_activate_policy(q, &blkcg_policy_iocost);
if (ret) {
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From a0195f314a25582b38993bf30db11c300f4f4611 Mon Sep 17 00:00:00 2001
From: Fenghua Yu <fenghua.yu(a)intel.com>
Date: Thu, 17 Dec 2020 14:31:19 -0800
Subject: [PATCH] x86/resctrl: Don't move a task to the same resource group
Shakeel Butt reported in [1] that a user can request a task to be moved
to a resource group even if the task is already in the group. It just
wastes time to do the move operation which could be costly to send IPI
to a different CPU.
Add a sanity check to ensure that the move operation only happens when
the task is not already in the resource group.
[1] https://lore.kernel.org/lkml/CALvZod7E9zzHwenzf7objzGKsdBmVwTgEJ0nPgs0LUFU3…
Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files")
Reported-by: Shakeel Butt <shakeelb(a)google.com>
Signed-off-by: Fenghua Yu <fenghua.yu(a)intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/962ede65d8e95be793cb61102cca37f7bb018e66.16082431…
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1c6f8a60ac52..460f3e0df106 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -546,6 +546,13 @@ static void update_task_closid_rmid(struct task_struct *t)
static int __rdtgroup_move_task(struct task_struct *tsk,
struct rdtgroup *rdtgrp)
{
+ /* If the task is already in rdtgrp, no need to move the task. */
+ if ((rdtgrp->type == RDTCTRL_GROUP && tsk->closid == rdtgrp->closid &&
+ tsk->rmid == rdtgrp->mon.rmid) ||
+ (rdtgrp->type == RDTMON_GROUP && tsk->rmid == rdtgrp->mon.rmid &&
+ tsk->closid == rdtgrp->mon.parent->closid))
+ return 0;
+
/*
* Set the task's closid/rmid before the PQR_ASSOC MSR can be
* updated by them.
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From a0195f314a25582b38993bf30db11c300f4f4611 Mon Sep 17 00:00:00 2001
From: Fenghua Yu <fenghua.yu(a)intel.com>
Date: Thu, 17 Dec 2020 14:31:19 -0800
Subject: [PATCH] x86/resctrl: Don't move a task to the same resource group
Shakeel Butt reported in [1] that a user can request a task to be moved
to a resource group even if the task is already in the group. It just
wastes time to do the move operation which could be costly to send IPI
to a different CPU.
Add a sanity check to ensure that the move operation only happens when
the task is not already in the resource group.
[1] https://lore.kernel.org/lkml/CALvZod7E9zzHwenzf7objzGKsdBmVwTgEJ0nPgs0LUFU3…
Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files")
Reported-by: Shakeel Butt <shakeelb(a)google.com>
Signed-off-by: Fenghua Yu <fenghua.yu(a)intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/962ede65d8e95be793cb61102cca37f7bb018e66.16082431…
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1c6f8a60ac52..460f3e0df106 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -546,6 +546,13 @@ static void update_task_closid_rmid(struct task_struct *t)
static int __rdtgroup_move_task(struct task_struct *tsk,
struct rdtgroup *rdtgrp)
{
+ /* If the task is already in rdtgrp, no need to move the task. */
+ if ((rdtgrp->type == RDTCTRL_GROUP && tsk->closid == rdtgrp->closid &&
+ tsk->rmid == rdtgrp->mon.rmid) ||
+ (rdtgrp->type == RDTMON_GROUP && tsk->rmid == rdtgrp->mon.rmid &&
+ tsk->closid == rdtgrp->mon.parent->closid))
+ return 0;
+
/*
* Set the task's closid/rmid before the PQR_ASSOC MSR can be
* updated by them.
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From a0195f314a25582b38993bf30db11c300f4f4611 Mon Sep 17 00:00:00 2001
From: Fenghua Yu <fenghua.yu(a)intel.com>
Date: Thu, 17 Dec 2020 14:31:19 -0800
Subject: [PATCH] x86/resctrl: Don't move a task to the same resource group
Shakeel Butt reported in [1] that a user can request a task to be moved
to a resource group even if the task is already in the group. It just
wastes time to do the move operation which could be costly to send IPI
to a different CPU.
Add a sanity check to ensure that the move operation only happens when
the task is not already in the resource group.
[1] https://lore.kernel.org/lkml/CALvZod7E9zzHwenzf7objzGKsdBmVwTgEJ0nPgs0LUFU3…
Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files")
Reported-by: Shakeel Butt <shakeelb(a)google.com>
Signed-off-by: Fenghua Yu <fenghua.yu(a)intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/962ede65d8e95be793cb61102cca37f7bb018e66.16082431…
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1c6f8a60ac52..460f3e0df106 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -546,6 +546,13 @@ static void update_task_closid_rmid(struct task_struct *t)
static int __rdtgroup_move_task(struct task_struct *tsk,
struct rdtgroup *rdtgrp)
{
+ /* If the task is already in rdtgrp, no need to move the task. */
+ if ((rdtgrp->type == RDTCTRL_GROUP && tsk->closid == rdtgrp->closid &&
+ tsk->rmid == rdtgrp->mon.rmid) ||
+ (rdtgrp->type == RDTMON_GROUP && tsk->rmid == rdtgrp->mon.rmid &&
+ tsk->closid == rdtgrp->mon.parent->closid))
+ return 0;
+
/*
* Set the task's closid/rmid before the PQR_ASSOC MSR can be
* updated by them.
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 88bf56d04bc3564542049ec4ec168a8b60d0b48c Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs(a)linux.alibaba.com>
Date: Thu, 17 Dec 2020 23:41:18 +0800
Subject: [PATCH] kvm: check tlbs_dirty directly
In kvm_mmu_notifier_invalidate_range_start(), tlbs_dirty is used as:
need_tlb_flush |= kvm->tlbs_dirty;
with need_tlb_flush's type being int and tlbs_dirty's type being long.
It means that tlbs_dirty is always used as int and the higher 32 bits
is useless. We need to check tlbs_dirty in a correct way and this
change checks it directly without propagating it to need_tlb_flush.
Note: it's _extremely_ unlikely this neglecting of higher 32 bits can
cause problems in practice. It would require encountering tlbs_dirty
on a 4 billion count boundary, and KVM would need to be using shadow
paging or be running a nested guest.
Cc: stable(a)vger.kernel.org
Fixes: a4ee1ca4a36e ("KVM: MMU: delay flush all tlbs on sync_page path")
Signed-off-by: Lai Jiangshan <laijs(a)linux.alibaba.com>
Message-Id: <20201217154118.16497-1-jiangshanlai(a)gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3abcb2ce5b7d..19dae28904f7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -485,9 +485,8 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
kvm->mmu_notifier_count++;
need_tlb_flush = kvm_unmap_hva_range(kvm, range->start, range->end,
range->flags);
- need_tlb_flush |= kvm->tlbs_dirty;
/* we've to flush the tlb before the pages can be freed */
- if (need_tlb_flush)
+ if (need_tlb_flush || kvm->tlbs_dirty)
kvm_flush_remote_tlbs(kvm);
spin_unlock(&kvm->mmu_lock);