The patch below does not apply to the 5.15-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x f41e355f8b48d894324a3fdc9727e08b1bce78e2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072919-voyage-outline-047b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
f41e355f8b48 ("nilfs2: fix incorrect inode allocation from reserved inodes")
af6eae646851 ("nilfs2: convert persistent object allocator to use kmap_local")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f41e355f8b48d894324a3fdc9727e08b1bce78e2 Mon Sep 17 00:00:00 2001
From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Date: Sun, 23 Jun 2024 14:11:35 +0900
Subject: [PATCH] nilfs2: fix incorrect inode allocation from reserved inodes
If the bitmap block that manages the inode allocation status is corrupted,
nilfs_ifile_create_inode() may allocate a new inode from the reserved
inode area where it should not be allocated.
Previous fix commit d325dc6eb763 ("nilfs2: fix use-after-free bug of
struct nilfs_root"), fixed the problem that reserved inodes with inode
numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
bitmap corruption, but since the start number of non-reserved inodes is
read from the super block and may change, in which case inode allocation
may occur from the extended reserved inode area.
If that happens, access to that inode will cause an IO error, causing the
file system to degrade to an error state.
Fix this potential issue by adding a wraparound option to the common
metadata object allocation routine and by modifying
nilfs_ifile_create_inode() to disable the option so that it only allocates
inodes with inode numbers greater than or equal to the inode number read
in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
inodes.
Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Cc: Hillf Danton <hdanton(a)sina.com>
Cc: Jan Kara <jack(a)suse.cz>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index 89caef7513db..ba50388ee4bf 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -377,11 +377,12 @@ void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
* @target: offset number of an entry in the group (start point)
* @bsize: size in bits
* @lock: spin lock protecting @bitmap
+ * @wrap: whether to wrap around
*/
static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
unsigned long target,
unsigned int bsize,
- spinlock_t *lock)
+ spinlock_t *lock, bool wrap)
{
int pos, end = bsize;
@@ -397,6 +398,8 @@ static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
end = target;
}
+ if (!wrap)
+ return -ENOSPC;
/* wrap around */
for (pos = 0; pos < end; pos++) {
@@ -495,9 +498,10 @@ int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
+ * @wrap: whether to wrap around
*/
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
- struct nilfs_palloc_req *req)
+ struct nilfs_palloc_req *req, bool wrap)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
@@ -516,7 +520,7 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
entries_per_group = nilfs_palloc_entries_per_group(inode);
for (i = 0; i < ngroups; i += n) {
- if (group >= ngroups) {
+ if (group >= ngroups && wrap) {
/* wrap around */
group = 0;
maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
@@ -550,7 +554,14 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
pos = nilfs_palloc_find_available_slot(
- bitmap, group_offset, entries_per_group, lock);
+ bitmap, group_offset, entries_per_group, lock,
+ wrap);
+ /*
+ * Since the search for a free slot in the second and
+ * subsequent bitmap blocks always starts from the
+ * beginning, the wrap flag only has an effect on the
+ * first search.
+ */
kunmap_local(bitmap_kaddr);
if (pos >= 0)
goto found;
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index b667e869ac07..d825a9faca6d 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -50,8 +50,8 @@ struct nilfs_palloc_req {
struct buffer_head *pr_entry_bh;
};
-int nilfs_palloc_prepare_alloc_entry(struct inode *,
- struct nilfs_palloc_req *);
+int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
+ struct nilfs_palloc_req *req, bool wrap);
void nilfs_palloc_commit_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c
index 180fc8d36213..fc1caf63a42a 100644
--- a/fs/nilfs2/dat.c
+++ b/fs/nilfs2/dat.c
@@ -75,7 +75,7 @@ int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
int ret;
- ret = nilfs_palloc_prepare_alloc_entry(dat, req);
+ ret = nilfs_palloc_prepare_alloc_entry(dat, req, true);
if (ret < 0)
return ret;
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index 612e609158b5..1e86b9303b7c 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -56,13 +56,10 @@ int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
struct nilfs_palloc_req req;
int ret;
- req.pr_entry_nr = 0; /*
- * 0 says find free inode from beginning
- * of a group. dull code!!
- */
+ req.pr_entry_nr = NILFS_FIRST_INO(ifile->i_sb);
req.pr_entry_bh = NULL;
- ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
+ ret = nilfs_palloc_prepare_alloc_entry(ifile, &req, false);
if (!ret) {
ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
&req.pr_entry_bh);
The patch below does not apply to the 6.1-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x f41e355f8b48d894324a3fdc9727e08b1bce78e2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072917-crumpet-velcro-eae5@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
f41e355f8b48 ("nilfs2: fix incorrect inode allocation from reserved inodes")
af6eae646851 ("nilfs2: convert persistent object allocator to use kmap_local")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f41e355f8b48d894324a3fdc9727e08b1bce78e2 Mon Sep 17 00:00:00 2001
From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Date: Sun, 23 Jun 2024 14:11:35 +0900
Subject: [PATCH] nilfs2: fix incorrect inode allocation from reserved inodes
If the bitmap block that manages the inode allocation status is corrupted,
nilfs_ifile_create_inode() may allocate a new inode from the reserved
inode area where it should not be allocated.
Previous fix commit d325dc6eb763 ("nilfs2: fix use-after-free bug of
struct nilfs_root"), fixed the problem that reserved inodes with inode
numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
bitmap corruption, but since the start number of non-reserved inodes is
read from the super block and may change, in which case inode allocation
may occur from the extended reserved inode area.
If that happens, access to that inode will cause an IO error, causing the
file system to degrade to an error state.
Fix this potential issue by adding a wraparound option to the common
metadata object allocation routine and by modifying
nilfs_ifile_create_inode() to disable the option so that it only allocates
inodes with inode numbers greater than or equal to the inode number read
in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
inodes.
Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Cc: Hillf Danton <hdanton(a)sina.com>
Cc: Jan Kara <jack(a)suse.cz>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index 89caef7513db..ba50388ee4bf 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -377,11 +377,12 @@ void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
* @target: offset number of an entry in the group (start point)
* @bsize: size in bits
* @lock: spin lock protecting @bitmap
+ * @wrap: whether to wrap around
*/
static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
unsigned long target,
unsigned int bsize,
- spinlock_t *lock)
+ spinlock_t *lock, bool wrap)
{
int pos, end = bsize;
@@ -397,6 +398,8 @@ static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
end = target;
}
+ if (!wrap)
+ return -ENOSPC;
/* wrap around */
for (pos = 0; pos < end; pos++) {
@@ -495,9 +498,10 @@ int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
+ * @wrap: whether to wrap around
*/
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
- struct nilfs_palloc_req *req)
+ struct nilfs_palloc_req *req, bool wrap)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
@@ -516,7 +520,7 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
entries_per_group = nilfs_palloc_entries_per_group(inode);
for (i = 0; i < ngroups; i += n) {
- if (group >= ngroups) {
+ if (group >= ngroups && wrap) {
/* wrap around */
group = 0;
maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
@@ -550,7 +554,14 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
pos = nilfs_palloc_find_available_slot(
- bitmap, group_offset, entries_per_group, lock);
+ bitmap, group_offset, entries_per_group, lock,
+ wrap);
+ /*
+ * Since the search for a free slot in the second and
+ * subsequent bitmap blocks always starts from the
+ * beginning, the wrap flag only has an effect on the
+ * first search.
+ */
kunmap_local(bitmap_kaddr);
if (pos >= 0)
goto found;
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index b667e869ac07..d825a9faca6d 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -50,8 +50,8 @@ struct nilfs_palloc_req {
struct buffer_head *pr_entry_bh;
};
-int nilfs_palloc_prepare_alloc_entry(struct inode *,
- struct nilfs_palloc_req *);
+int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
+ struct nilfs_palloc_req *req, bool wrap);
void nilfs_palloc_commit_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c
index 180fc8d36213..fc1caf63a42a 100644
--- a/fs/nilfs2/dat.c
+++ b/fs/nilfs2/dat.c
@@ -75,7 +75,7 @@ int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
int ret;
- ret = nilfs_palloc_prepare_alloc_entry(dat, req);
+ ret = nilfs_palloc_prepare_alloc_entry(dat, req, true);
if (ret < 0)
return ret;
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index 612e609158b5..1e86b9303b7c 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -56,13 +56,10 @@ int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
struct nilfs_palloc_req req;
int ret;
- req.pr_entry_nr = 0; /*
- * 0 says find free inode from beginning
- * of a group. dull code!!
- */
+ req.pr_entry_nr = NILFS_FIRST_INO(ifile->i_sb);
req.pr_entry_bh = NULL;
- ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
+ ret = nilfs_palloc_prepare_alloc_entry(ifile, &req, false);
if (!ret) {
ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
&req.pr_entry_bh);
The patch below does not apply to the 6.6-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x f41e355f8b48d894324a3fdc9727e08b1bce78e2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072914-egotistic-crewmate-8f1b@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
f41e355f8b48 ("nilfs2: fix incorrect inode allocation from reserved inodes")
af6eae646851 ("nilfs2: convert persistent object allocator to use kmap_local")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f41e355f8b48d894324a3fdc9727e08b1bce78e2 Mon Sep 17 00:00:00 2001
From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Date: Sun, 23 Jun 2024 14:11:35 +0900
Subject: [PATCH] nilfs2: fix incorrect inode allocation from reserved inodes
If the bitmap block that manages the inode allocation status is corrupted,
nilfs_ifile_create_inode() may allocate a new inode from the reserved
inode area where it should not be allocated.
Previous fix commit d325dc6eb763 ("nilfs2: fix use-after-free bug of
struct nilfs_root"), fixed the problem that reserved inodes with inode
numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
bitmap corruption, but since the start number of non-reserved inodes is
read from the super block and may change, in which case inode allocation
may occur from the extended reserved inode area.
If that happens, access to that inode will cause an IO error, causing the
file system to degrade to an error state.
Fix this potential issue by adding a wraparound option to the common
metadata object allocation routine and by modifying
nilfs_ifile_create_inode() to disable the option so that it only allocates
inodes with inode numbers greater than or equal to the inode number read
in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
inodes.
Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Cc: Hillf Danton <hdanton(a)sina.com>
Cc: Jan Kara <jack(a)suse.cz>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index 89caef7513db..ba50388ee4bf 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -377,11 +377,12 @@ void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
* @target: offset number of an entry in the group (start point)
* @bsize: size in bits
* @lock: spin lock protecting @bitmap
+ * @wrap: whether to wrap around
*/
static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
unsigned long target,
unsigned int bsize,
- spinlock_t *lock)
+ spinlock_t *lock, bool wrap)
{
int pos, end = bsize;
@@ -397,6 +398,8 @@ static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
end = target;
}
+ if (!wrap)
+ return -ENOSPC;
/* wrap around */
for (pos = 0; pos < end; pos++) {
@@ -495,9 +498,10 @@ int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
+ * @wrap: whether to wrap around
*/
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
- struct nilfs_palloc_req *req)
+ struct nilfs_palloc_req *req, bool wrap)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
@@ -516,7 +520,7 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
entries_per_group = nilfs_palloc_entries_per_group(inode);
for (i = 0; i < ngroups; i += n) {
- if (group >= ngroups) {
+ if (group >= ngroups && wrap) {
/* wrap around */
group = 0;
maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
@@ -550,7 +554,14 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
pos = nilfs_palloc_find_available_slot(
- bitmap, group_offset, entries_per_group, lock);
+ bitmap, group_offset, entries_per_group, lock,
+ wrap);
+ /*
+ * Since the search for a free slot in the second and
+ * subsequent bitmap blocks always starts from the
+ * beginning, the wrap flag only has an effect on the
+ * first search.
+ */
kunmap_local(bitmap_kaddr);
if (pos >= 0)
goto found;
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index b667e869ac07..d825a9faca6d 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -50,8 +50,8 @@ struct nilfs_palloc_req {
struct buffer_head *pr_entry_bh;
};
-int nilfs_palloc_prepare_alloc_entry(struct inode *,
- struct nilfs_palloc_req *);
+int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
+ struct nilfs_palloc_req *req, bool wrap);
void nilfs_palloc_commit_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c
index 180fc8d36213..fc1caf63a42a 100644
--- a/fs/nilfs2/dat.c
+++ b/fs/nilfs2/dat.c
@@ -75,7 +75,7 @@ int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
int ret;
- ret = nilfs_palloc_prepare_alloc_entry(dat, req);
+ ret = nilfs_palloc_prepare_alloc_entry(dat, req, true);
if (ret < 0)
return ret;
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index 612e609158b5..1e86b9303b7c 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -56,13 +56,10 @@ int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
struct nilfs_palloc_req req;
int ret;
- req.pr_entry_nr = 0; /*
- * 0 says find free inode from beginning
- * of a group. dull code!!
- */
+ req.pr_entry_nr = NILFS_FIRST_INO(ifile->i_sb);
req.pr_entry_bh = NULL;
- ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
+ ret = nilfs_palloc_prepare_alloc_entry(ifile, &req, false);
if (!ret) {
ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
&req.pr_entry_bh);
The patch below does not apply to the 6.10-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.10.y
git checkout FETCH_HEAD
git cherry-pick -x f41e355f8b48d894324a3fdc9727e08b1bce78e2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072913-overcrowd-affair-324f@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^..
Possible dependencies:
f41e355f8b48 ("nilfs2: fix incorrect inode allocation from reserved inodes")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f41e355f8b48d894324a3fdc9727e08b1bce78e2 Mon Sep 17 00:00:00 2001
From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Date: Sun, 23 Jun 2024 14:11:35 +0900
Subject: [PATCH] nilfs2: fix incorrect inode allocation from reserved inodes
If the bitmap block that manages the inode allocation status is corrupted,
nilfs_ifile_create_inode() may allocate a new inode from the reserved
inode area where it should not be allocated.
Previous fix commit d325dc6eb763 ("nilfs2: fix use-after-free bug of
struct nilfs_root"), fixed the problem that reserved inodes with inode
numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
bitmap corruption, but since the start number of non-reserved inodes is
read from the super block and may change, in which case inode allocation
may occur from the extended reserved inode area.
If that happens, access to that inode will cause an IO error, causing the
file system to degrade to an error state.
Fix this potential issue by adding a wraparound option to the common
metadata object allocation routine and by modifying
nilfs_ifile_create_inode() to disable the option so that it only allocates
inodes with inode numbers greater than or equal to the inode number read
in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
inodes.
Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Cc: Hillf Danton <hdanton(a)sina.com>
Cc: Jan Kara <jack(a)suse.cz>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index 89caef7513db..ba50388ee4bf 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -377,11 +377,12 @@ void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
* @target: offset number of an entry in the group (start point)
* @bsize: size in bits
* @lock: spin lock protecting @bitmap
+ * @wrap: whether to wrap around
*/
static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
unsigned long target,
unsigned int bsize,
- spinlock_t *lock)
+ spinlock_t *lock, bool wrap)
{
int pos, end = bsize;
@@ -397,6 +398,8 @@ static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
end = target;
}
+ if (!wrap)
+ return -ENOSPC;
/* wrap around */
for (pos = 0; pos < end; pos++) {
@@ -495,9 +498,10 @@ int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
+ * @wrap: whether to wrap around
*/
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
- struct nilfs_palloc_req *req)
+ struct nilfs_palloc_req *req, bool wrap)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
@@ -516,7 +520,7 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
entries_per_group = nilfs_palloc_entries_per_group(inode);
for (i = 0; i < ngroups; i += n) {
- if (group >= ngroups) {
+ if (group >= ngroups && wrap) {
/* wrap around */
group = 0;
maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
@@ -550,7 +554,14 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
pos = nilfs_palloc_find_available_slot(
- bitmap, group_offset, entries_per_group, lock);
+ bitmap, group_offset, entries_per_group, lock,
+ wrap);
+ /*
+ * Since the search for a free slot in the second and
+ * subsequent bitmap blocks always starts from the
+ * beginning, the wrap flag only has an effect on the
+ * first search.
+ */
kunmap_local(bitmap_kaddr);
if (pos >= 0)
goto found;
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index b667e869ac07..d825a9faca6d 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -50,8 +50,8 @@ struct nilfs_palloc_req {
struct buffer_head *pr_entry_bh;
};
-int nilfs_palloc_prepare_alloc_entry(struct inode *,
- struct nilfs_palloc_req *);
+int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
+ struct nilfs_palloc_req *req, bool wrap);
void nilfs_palloc_commit_alloc_entry(struct inode *,
struct nilfs_palloc_req *);
void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c
index 180fc8d36213..fc1caf63a42a 100644
--- a/fs/nilfs2/dat.c
+++ b/fs/nilfs2/dat.c
@@ -75,7 +75,7 @@ int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
int ret;
- ret = nilfs_palloc_prepare_alloc_entry(dat, req);
+ ret = nilfs_palloc_prepare_alloc_entry(dat, req, true);
if (ret < 0)
return ret;
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index 612e609158b5..1e86b9303b7c 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -56,13 +56,10 @@ int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
struct nilfs_palloc_req req;
int ret;
- req.pr_entry_nr = 0; /*
- * 0 says find free inode from beginning
- * of a group. dull code!!
- */
+ req.pr_entry_nr = NILFS_FIRST_INO(ifile->i_sb);
req.pr_entry_bh = NULL;
- ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
+ ret = nilfs_palloc_prepare_alloc_entry(ifile, &req, false);
if (!ret) {
ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
&req.pr_entry_bh);
The patch below does not apply to the 6.6-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 66eca1021a42856d6af2a9802c99e160278aed91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072902-yippee-superbowl-f065@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
66eca1021a42 ("mm/page_alloc: fix pcp->count race between drain_pages_zone() vs __rmqueue_pcplist()")
55f77df7d715 ("mm: page_alloc: control latency caused by zone PCP draining")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 66eca1021a42856d6af2a9802c99e160278aed91 Mon Sep 17 00:00:00 2001
From: Li Zhijian <lizhijian(a)fujitsu.com>
Date: Tue, 23 Jul 2024 14:44:28 +0800
Subject: [PATCH] mm/page_alloc: fix pcp->count race between drain_pages_zone()
vs __rmqueue_pcplist()
It's expected that no page should be left in pcp_list after calling
zone_pcp_disable() in offline_pages(). Previously, it's observed that
offline_pages() gets stuck [1] due to some pages remaining in pcp_list.
Cause:
There is a race condition between drain_pages_zone() and __rmqueue_pcplist()
involving the pcp->count variable. See below scenario:
CPU0 CPU1
---------------- ---------------
spin_lock(&pcp->lock);
__rmqueue_pcplist() {
zone_pcp_disable() {
/* list is empty */
if (list_empty(list)) {
/* add pages to pcp_list */
alloced = rmqueue_bulk()
mutex_lock(&pcp_batch_high_lock)
...
__drain_all_pages() {
drain_pages_zone() {
/* read pcp->count, it's 0 here */
count = READ_ONCE(pcp->count)
/* 0 means nothing to drain */
/* update pcp->count */
pcp->count += alloced << order;
...
...
spin_unlock(&pcp->lock);
In this case, after calling zone_pcp_disable() though, there are still some
pages in pcp_list. And these pages in pcp_list are neither movable nor
isolated, offline_pages() gets stuck as a result.
Solution:
Expand the scope of the pcp->lock to also protect pcp->count in
drain_pages_zone(), to ensure no pages are left in the pcp list after
zone_pcp_disable()
[1] https://lore.kernel.org/linux-mm/6a07125f-e720-404c-b2f9-e55f3f166e85@fujit…
Link: https://lkml.kernel.org/r/20240723064428.1179519-1-lizhijian@fujitsu.com
Fixes: 4b23a68f9536 ("mm/page_alloc: protect PCP lists with a spinlock")
Signed-off-by: Li Zhijian <lizhijian(a)fujitsu.com>
Reported-by: Yao Xingtao <yaoxt.fnst(a)fujitsu.com>
Reviewed-by: Vlastimil Babka <vbabka(a)suse.cz>
Cc: David Hildenbrand <david(a)redhat.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7ac8d61148fe..28f80daf5c04 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2343,16 +2343,20 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
static void drain_pages_zone(unsigned int cpu, struct zone *zone)
{
struct per_cpu_pages *pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
- int count = READ_ONCE(pcp->count);
-
- while (count) {
- int to_drain = min(count, pcp->batch << CONFIG_PCP_BATCH_SCALE_MAX);
- count -= to_drain;
+ int count;
+ do {
spin_lock(&pcp->lock);
- free_pcppages_bulk(zone, to_drain, pcp, 0);
+ count = pcp->count;
+ if (count) {
+ int to_drain = min(count,
+ pcp->batch << CONFIG_PCP_BATCH_SCALE_MAX);
+
+ free_pcppages_bulk(zone, to_drain, pcp, 0);
+ count -= to_drain;
+ }
spin_unlock(&pcp->lock);
- }
+ } while (count);
}
/*
The patch below does not apply to the 6.1-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 66eca1021a42856d6af2a9802c99e160278aed91
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072954-blaspheme-safeness-fcbc@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
66eca1021a42 ("mm/page_alloc: fix pcp->count race between drain_pages_zone() vs __rmqueue_pcplist()")
55f77df7d715 ("mm: page_alloc: control latency caused by zone PCP draining")
574907741599 ("mm/page_alloc: leave IRQs enabled for per-cpu page allocations")
c3e58a70425a ("mm/page_alloc: always remove pages from temporary list")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 66eca1021a42856d6af2a9802c99e160278aed91 Mon Sep 17 00:00:00 2001
From: Li Zhijian <lizhijian(a)fujitsu.com>
Date: Tue, 23 Jul 2024 14:44:28 +0800
Subject: [PATCH] mm/page_alloc: fix pcp->count race between drain_pages_zone()
vs __rmqueue_pcplist()
It's expected that no page should be left in pcp_list after calling
zone_pcp_disable() in offline_pages(). Previously, it's observed that
offline_pages() gets stuck [1] due to some pages remaining in pcp_list.
Cause:
There is a race condition between drain_pages_zone() and __rmqueue_pcplist()
involving the pcp->count variable. See below scenario:
CPU0 CPU1
---------------- ---------------
spin_lock(&pcp->lock);
__rmqueue_pcplist() {
zone_pcp_disable() {
/* list is empty */
if (list_empty(list)) {
/* add pages to pcp_list */
alloced = rmqueue_bulk()
mutex_lock(&pcp_batch_high_lock)
...
__drain_all_pages() {
drain_pages_zone() {
/* read pcp->count, it's 0 here */
count = READ_ONCE(pcp->count)
/* 0 means nothing to drain */
/* update pcp->count */
pcp->count += alloced << order;
...
...
spin_unlock(&pcp->lock);
In this case, after calling zone_pcp_disable() though, there are still some
pages in pcp_list. And these pages in pcp_list are neither movable nor
isolated, offline_pages() gets stuck as a result.
Solution:
Expand the scope of the pcp->lock to also protect pcp->count in
drain_pages_zone(), to ensure no pages are left in the pcp list after
zone_pcp_disable()
[1] https://lore.kernel.org/linux-mm/6a07125f-e720-404c-b2f9-e55f3f166e85@fujit…
Link: https://lkml.kernel.org/r/20240723064428.1179519-1-lizhijian@fujitsu.com
Fixes: 4b23a68f9536 ("mm/page_alloc: protect PCP lists with a spinlock")
Signed-off-by: Li Zhijian <lizhijian(a)fujitsu.com>
Reported-by: Yao Xingtao <yaoxt.fnst(a)fujitsu.com>
Reviewed-by: Vlastimil Babka <vbabka(a)suse.cz>
Cc: David Hildenbrand <david(a)redhat.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7ac8d61148fe..28f80daf5c04 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2343,16 +2343,20 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
static void drain_pages_zone(unsigned int cpu, struct zone *zone)
{
struct per_cpu_pages *pcp = per_cpu_ptr(zone->per_cpu_pageset, cpu);
- int count = READ_ONCE(pcp->count);
-
- while (count) {
- int to_drain = min(count, pcp->batch << CONFIG_PCP_BATCH_SCALE_MAX);
- count -= to_drain;
+ int count;
+ do {
spin_lock(&pcp->lock);
- free_pcppages_bulk(zone, to_drain, pcp, 0);
+ count = pcp->count;
+ if (count) {
+ int to_drain = min(count,
+ pcp->batch << CONFIG_PCP_BATCH_SCALE_MAX);
+
+ free_pcppages_bulk(zone, to_drain, pcp, 0);
+ count -= to_drain;
+ }
spin_unlock(&pcp->lock);
- }
+ } while (count);
}
/*
The patch below does not apply to the 6.6-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 11a1f4bc47362700fcbde717292158873fb847ed
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072919-usual-unstopped-30af@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
11a1f4bc4736 ("PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 11a1f4bc47362700fcbde717292158873fb847ed Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas(a)wunner.de>
Date: Tue, 18 Jun 2024 12:54:55 +0200
Subject: [PATCH] PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Keith reports a use-after-free when a DPC event occurs concurrently to
hot-removal of the same portion of the hierarchy:
The dpc_handler() awaits readiness of the secondary bus below the
Downstream Port where the DPC event occurred. To do so, it polls the
config space of the first child device on the secondary bus. If that
child device is concurrently removed, accesses to its struct pci_dev
cause the kernel to oops.
That's because pci_bridge_wait_for_secondary_bus() neglects to hold a
reference on the child device. Before v6.3, the function was only
called on resume from system sleep or on runtime resume. Holding a
reference wasn't necessary back then because the pciehp IRQ thread
could never run concurrently. (On resume from system sleep, IRQs are
not enabled until after the resume_noirq phase. And runtime resume is
always awaited before a PCI device is removed.)
However starting with v6.3, pci_bridge_wait_for_secondary_bus() is also
called on a DPC event. Commit 53b54ad074de ("PCI/DPC: Await readiness
of secondary bus after reset"), which introduced that, failed to
appreciate that pci_bridge_wait_for_secondary_bus() now needs to hold a
reference on the child device because dpc_handler() and pciehp may
indeed run concurrently. The commit was backported to v5.10+ stable
kernels, so that's the oldest one affected.
Add the missing reference acquisition.
Abridged stack trace:
BUG: unable to handle page fault for address: 00000000091400c0
CPU: 15 PID: 2464 Comm: irq/53-pcie-dpc 6.9.0
RIP: pci_bus_read_config_dword+0x17/0x50
pci_dev_wait()
pci_bridge_wait_for_secondary_bus()
dpc_reset_link()
pcie_do_recovery()
dpc_handler()
Fixes: 53b54ad074de ("PCI/DPC: Await readiness of secondary bus after reset")
Closes: https://lore.kernel.org/r/20240612181625.3604512-3-kbusch@meta.com/
Link: https://lore.kernel.org/linux-pci/8e4bcd4116fd94f592f2bf2749f168099c480ddf.…
Reported-by: Keith Busch <kbusch(a)kernel.org>
Tested-by: Keith Busch <kbusch(a)kernel.org>
Signed-off-by: Lukas Wunner <lukas(a)wunner.de>
Signed-off-by: Krzysztof Wilczyński <kwilczynski(a)kernel.org>
Reviewed-by: Keith Busch <kbusch(a)kernel.org>
Reviewed-by: Mika Westerberg <mika.westerberg(a)linux.intel.com>
Cc: stable(a)vger.kernel.org # v5.10+
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 59e0949fb079..c40a6c11e959 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4753,7 +4753,7 @@ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
*/
int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
{
- struct pci_dev *child;
+ struct pci_dev *child __free(pci_dev_put) = NULL;
int delay;
if (pci_dev_is_disconnected(dev))
@@ -4782,8 +4782,8 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
return 0;
}
- child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
- bus_list);
+ child = pci_dev_get(list_first_entry(&dev->subordinate->devices,
+ struct pci_dev, bus_list));
up_read(&pci_bus_sem);
/*
The patch below does not apply to the 6.1-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 11a1f4bc47362700fcbde717292158873fb847ed
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072918-headache-absently-933a@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
11a1f4bc4736 ("PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 11a1f4bc47362700fcbde717292158873fb847ed Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas(a)wunner.de>
Date: Tue, 18 Jun 2024 12:54:55 +0200
Subject: [PATCH] PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Keith reports a use-after-free when a DPC event occurs concurrently to
hot-removal of the same portion of the hierarchy:
The dpc_handler() awaits readiness of the secondary bus below the
Downstream Port where the DPC event occurred. To do so, it polls the
config space of the first child device on the secondary bus. If that
child device is concurrently removed, accesses to its struct pci_dev
cause the kernel to oops.
That's because pci_bridge_wait_for_secondary_bus() neglects to hold a
reference on the child device. Before v6.3, the function was only
called on resume from system sleep or on runtime resume. Holding a
reference wasn't necessary back then because the pciehp IRQ thread
could never run concurrently. (On resume from system sleep, IRQs are
not enabled until after the resume_noirq phase. And runtime resume is
always awaited before a PCI device is removed.)
However starting with v6.3, pci_bridge_wait_for_secondary_bus() is also
called on a DPC event. Commit 53b54ad074de ("PCI/DPC: Await readiness
of secondary bus after reset"), which introduced that, failed to
appreciate that pci_bridge_wait_for_secondary_bus() now needs to hold a
reference on the child device because dpc_handler() and pciehp may
indeed run concurrently. The commit was backported to v5.10+ stable
kernels, so that's the oldest one affected.
Add the missing reference acquisition.
Abridged stack trace:
BUG: unable to handle page fault for address: 00000000091400c0
CPU: 15 PID: 2464 Comm: irq/53-pcie-dpc 6.9.0
RIP: pci_bus_read_config_dword+0x17/0x50
pci_dev_wait()
pci_bridge_wait_for_secondary_bus()
dpc_reset_link()
pcie_do_recovery()
dpc_handler()
Fixes: 53b54ad074de ("PCI/DPC: Await readiness of secondary bus after reset")
Closes: https://lore.kernel.org/r/20240612181625.3604512-3-kbusch@meta.com/
Link: https://lore.kernel.org/linux-pci/8e4bcd4116fd94f592f2bf2749f168099c480ddf.…
Reported-by: Keith Busch <kbusch(a)kernel.org>
Tested-by: Keith Busch <kbusch(a)kernel.org>
Signed-off-by: Lukas Wunner <lukas(a)wunner.de>
Signed-off-by: Krzysztof Wilczyński <kwilczynski(a)kernel.org>
Reviewed-by: Keith Busch <kbusch(a)kernel.org>
Reviewed-by: Mika Westerberg <mika.westerberg(a)linux.intel.com>
Cc: stable(a)vger.kernel.org # v5.10+
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 59e0949fb079..c40a6c11e959 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4753,7 +4753,7 @@ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
*/
int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
{
- struct pci_dev *child;
+ struct pci_dev *child __free(pci_dev_put) = NULL;
int delay;
if (pci_dev_is_disconnected(dev))
@@ -4782,8 +4782,8 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
return 0;
}
- child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
- bus_list);
+ child = pci_dev_get(list_first_entry(&dev->subordinate->devices,
+ struct pci_dev, bus_list));
up_read(&pci_bus_sem);
/*
The patch below does not apply to the 5.15-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 11a1f4bc47362700fcbde717292158873fb847ed
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072921-crazed-babble-80d9@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
11a1f4bc4736 ("PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 11a1f4bc47362700fcbde717292158873fb847ed Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas(a)wunner.de>
Date: Tue, 18 Jun 2024 12:54:55 +0200
Subject: [PATCH] PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Keith reports a use-after-free when a DPC event occurs concurrently to
hot-removal of the same portion of the hierarchy:
The dpc_handler() awaits readiness of the secondary bus below the
Downstream Port where the DPC event occurred. To do so, it polls the
config space of the first child device on the secondary bus. If that
child device is concurrently removed, accesses to its struct pci_dev
cause the kernel to oops.
That's because pci_bridge_wait_for_secondary_bus() neglects to hold a
reference on the child device. Before v6.3, the function was only
called on resume from system sleep or on runtime resume. Holding a
reference wasn't necessary back then because the pciehp IRQ thread
could never run concurrently. (On resume from system sleep, IRQs are
not enabled until after the resume_noirq phase. And runtime resume is
always awaited before a PCI device is removed.)
However starting with v6.3, pci_bridge_wait_for_secondary_bus() is also
called on a DPC event. Commit 53b54ad074de ("PCI/DPC: Await readiness
of secondary bus after reset"), which introduced that, failed to
appreciate that pci_bridge_wait_for_secondary_bus() now needs to hold a
reference on the child device because dpc_handler() and pciehp may
indeed run concurrently. The commit was backported to v5.10+ stable
kernels, so that's the oldest one affected.
Add the missing reference acquisition.
Abridged stack trace:
BUG: unable to handle page fault for address: 00000000091400c0
CPU: 15 PID: 2464 Comm: irq/53-pcie-dpc 6.9.0
RIP: pci_bus_read_config_dword+0x17/0x50
pci_dev_wait()
pci_bridge_wait_for_secondary_bus()
dpc_reset_link()
pcie_do_recovery()
dpc_handler()
Fixes: 53b54ad074de ("PCI/DPC: Await readiness of secondary bus after reset")
Closes: https://lore.kernel.org/r/20240612181625.3604512-3-kbusch@meta.com/
Link: https://lore.kernel.org/linux-pci/8e4bcd4116fd94f592f2bf2749f168099c480ddf.…
Reported-by: Keith Busch <kbusch(a)kernel.org>
Tested-by: Keith Busch <kbusch(a)kernel.org>
Signed-off-by: Lukas Wunner <lukas(a)wunner.de>
Signed-off-by: Krzysztof Wilczyński <kwilczynski(a)kernel.org>
Reviewed-by: Keith Busch <kbusch(a)kernel.org>
Reviewed-by: Mika Westerberg <mika.westerberg(a)linux.intel.com>
Cc: stable(a)vger.kernel.org # v5.10+
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 59e0949fb079..c40a6c11e959 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4753,7 +4753,7 @@ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
*/
int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
{
- struct pci_dev *child;
+ struct pci_dev *child __free(pci_dev_put) = NULL;
int delay;
if (pci_dev_is_disconnected(dev))
@@ -4782,8 +4782,8 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
return 0;
}
- child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
- bus_list);
+ child = pci_dev_get(list_first_entry(&dev->subordinate->devices,
+ struct pci_dev, bus_list));
up_read(&pci_bus_sem);
/*
The patch below does not apply to the 5.10-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 11a1f4bc47362700fcbde717292158873fb847ed
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024072919-booted-rise-cc5d@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
11a1f4bc4736 ("PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 11a1f4bc47362700fcbde717292158873fb847ed Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas(a)wunner.de>
Date: Tue, 18 Jun 2024 12:54:55 +0200
Subject: [PATCH] PCI/DPC: Fix use-after-free on concurrent DPC and hot-removal
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Content-Transfer-Encoding: 8bit
Keith reports a use-after-free when a DPC event occurs concurrently to
hot-removal of the same portion of the hierarchy:
The dpc_handler() awaits readiness of the secondary bus below the
Downstream Port where the DPC event occurred. To do so, it polls the
config space of the first child device on the secondary bus. If that
child device is concurrently removed, accesses to its struct pci_dev
cause the kernel to oops.
That's because pci_bridge_wait_for_secondary_bus() neglects to hold a
reference on the child device. Before v6.3, the function was only
called on resume from system sleep or on runtime resume. Holding a
reference wasn't necessary back then because the pciehp IRQ thread
could never run concurrently. (On resume from system sleep, IRQs are
not enabled until after the resume_noirq phase. And runtime resume is
always awaited before a PCI device is removed.)
However starting with v6.3, pci_bridge_wait_for_secondary_bus() is also
called on a DPC event. Commit 53b54ad074de ("PCI/DPC: Await readiness
of secondary bus after reset"), which introduced that, failed to
appreciate that pci_bridge_wait_for_secondary_bus() now needs to hold a
reference on the child device because dpc_handler() and pciehp may
indeed run concurrently. The commit was backported to v5.10+ stable
kernels, so that's the oldest one affected.
Add the missing reference acquisition.
Abridged stack trace:
BUG: unable to handle page fault for address: 00000000091400c0
CPU: 15 PID: 2464 Comm: irq/53-pcie-dpc 6.9.0
RIP: pci_bus_read_config_dword+0x17/0x50
pci_dev_wait()
pci_bridge_wait_for_secondary_bus()
dpc_reset_link()
pcie_do_recovery()
dpc_handler()
Fixes: 53b54ad074de ("PCI/DPC: Await readiness of secondary bus after reset")
Closes: https://lore.kernel.org/r/20240612181625.3604512-3-kbusch@meta.com/
Link: https://lore.kernel.org/linux-pci/8e4bcd4116fd94f592f2bf2749f168099c480ddf.…
Reported-by: Keith Busch <kbusch(a)kernel.org>
Tested-by: Keith Busch <kbusch(a)kernel.org>
Signed-off-by: Lukas Wunner <lukas(a)wunner.de>
Signed-off-by: Krzysztof Wilczyński <kwilczynski(a)kernel.org>
Reviewed-by: Keith Busch <kbusch(a)kernel.org>
Reviewed-by: Mika Westerberg <mika.westerberg(a)linux.intel.com>
Cc: stable(a)vger.kernel.org # v5.10+
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 59e0949fb079..c40a6c11e959 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4753,7 +4753,7 @@ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
*/
int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
{
- struct pci_dev *child;
+ struct pci_dev *child __free(pci_dev_put) = NULL;
int delay;
if (pci_dev_is_disconnected(dev))
@@ -4782,8 +4782,8 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
return 0;
}
- child = list_first_entry(&dev->subordinate->devices, struct pci_dev,
- bus_list);
+ child = pci_dev_get(list_first_entry(&dev->subordinate->devices,
+ struct pci_dev, bus_list));
up_read(&pci_bus_sem);
/*