The quilt patch titled
Subject: nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()
has been removed from the -mm tree. Its filename was
nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Subject: nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()
Date: Wed, 10 May 2023 00:29:56 +0900
During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer(). However, since
nilfs_evict_inode() uses nilfs_root for some cleanup operations, it may
cause use-after-free read if inodes are left in "garbage_list" and
released by nilfs_dispose_list() at the end of nilfs_detach_log_writer().
Fix this issue by modifying nilfs_evict_inode() to only clear inode
without additional metadata changes that use nilfs_root if the file system
is degraded to read-only or the writer is detached.
Link: https://lkml.kernel.org/r/20230509152956.8313-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Reported-by: syzbot+78d4495558999f55d1da(a)syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000099e5ac05fb1c3b85@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/nilfs2/inode.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
--- a/fs/nilfs2/inode.c~nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode
+++ a/fs/nilfs2/inode.c
@@ -917,6 +917,7 @@ void nilfs_evict_inode(struct inode *ino
struct nilfs_transaction_info ti;
struct super_block *sb = inode->i_sb;
struct nilfs_inode_info *ii = NILFS_I(inode);
+ struct the_nilfs *nilfs;
int ret;
if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
@@ -929,6 +930,23 @@ void nilfs_evict_inode(struct inode *ino
truncate_inode_pages_final(&inode->i_data);
+ nilfs = sb->s_fs_info;
+ if (unlikely(sb_rdonly(sb) || !nilfs->ns_writer)) {
+ /*
+ * If this inode is about to be disposed after the file system
+ * has been degraded to read-only due to file system corruption
+ * or after the writer has been detached, do not make any
+ * changes that cause writes, just clear it.
+ * Do this check after read-locking ns_segctor_sem by
+ * nilfs_transaction_begin() in order to avoid a race with
+ * the writer detach operation.
+ */
+ clear_inode(inode);
+ nilfs_clear_inode(inode);
+ nilfs_transaction_abort(sb);
+ return;
+ }
+
/* TODO: some of the following operations may fail. */
nilfs_truncate_bmap(ii, 0);
nilfs_mark_inode_dirty(inode);
_
Patches currently in -mm which might be from konishi.ryusuke(a)gmail.com are
nilfs2-fix-incomplete-buffer-cleanup-in-nilfs_btnode_abort_change_key.patch
The quilt patch titled
Subject: mm: fix zswap writeback race condition
has been removed from the -mm tree. Its filename was
mm-fix-zswap-writeback-race-condition.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Domenico Cerasuolo <cerasuolodomenico(a)gmail.com>
Subject: mm: fix zswap writeback race condition
Date: Wed, 3 May 2023 17:12:00 +0200
The zswap writeback mechanism can cause a race condition resulting in
memory corruption, where a swapped out page gets swapped in with data that
was written to a different page.
The race unfolds like this:
1. a page with data A and swap offset X is stored in zswap
2. page A is removed off the LRU by zpool driver for writeback in
zswap-shrink work, data for A is mapped by zpool driver
3. user space program faults and invalidates page entry A, offset X is
considered free
4. kswapd stores page B at offset X in zswap (zswap could also be
full, if so, page B would then be IOed to X, then skip step 5.)
5. entry A is replaced by B in tree->rbroot, this doesn't affect the
local reference held by zswap-shrink work
6. zswap-shrink work writes back A at X, and frees zswap entry A
7. swapin of slot X brings A in memory instead of B
The fix:
Once the swap page cache has been allocated (case ZSWAP_SWAPCACHE_NEW),
zswap-shrink work just checks that the local zswap_entry reference is
still the same as the one in the tree. If it's not the same it means that
it's either been invalidated or replaced, in both cases the writeback is
aborted because the local entry contains stale data.
Reproducer:
I originally found this by running `stress` overnight to validate my work
on the zswap writeback mechanism, it manifested after hours on my test
machine. The key to make it happen is having zswap writebacks, so
whatever setup pumps /sys/kernel/debug/zswap/written_back_pages should do
the trick.
In order to reproduce this faster on a vm, I setup a system with ~100M of
available memory and a 500M swap file, then running `stress --vm 1
--vm-bytes 300000000 --vm-stride 4000` makes it happen in matter of tens
of minutes. One can speed things up even more by swinging
/sys/module/zswap/parameters/max_pool_percent up and down between, say, 20
and 1; this makes it reproduce in tens of seconds. It's crucial to set
`--vm-stride` to something other than 4096 otherwise `stress` won't
realize that memory has been corrupted because all pages would have the
same data.
Link: https://lkml.kernel.org/r/20230503151200.19707-1-cerasuolodomenico@gmail.com
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico(a)gmail.com>
Acked-by: Johannes Weiner <hannes(a)cmpxchg.org>
Reviewed-by: Chris Li (Google) <chrisl(a)kernel.org>
Cc: Dan Streetman <ddstreet(a)ieee.org>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Minchan Kim <minchan(a)kernel.org>
Cc: Nitin Gupta <ngupta(a)vflare.org>
Cc: Seth Jennings <sjenning(a)redhat.com>
Cc: Vitaly Wool <vitaly.wool(a)konsulko.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/zswap.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
--- a/mm/zswap.c~mm-fix-zswap-writeback-race-condition
+++ a/mm/zswap.c
@@ -1020,6 +1020,22 @@ static int zswap_writeback_entry(struct
goto fail;
case ZSWAP_SWAPCACHE_NEW: /* page is locked */
+ /*
+ * Having a local reference to the zswap entry doesn't exclude
+ * swapping from invalidating and recycling the swap slot. Once
+ * the swapcache is secured against concurrent swapping to and
+ * from the slot, recheck that the entry is still current before
+ * writing.
+ */
+ spin_lock(&tree->lock);
+ if (zswap_rb_search(&tree->rbroot, entry->offset) != entry) {
+ spin_unlock(&tree->lock);
+ delete_from_swap_cache(page_folio(page));
+ ret = -ENOMEM;
+ goto fail;
+ }
+ spin_unlock(&tree->lock);
+
/* decompress */
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
dlen = PAGE_SIZE;
_
Patches currently in -mm which might be from cerasuolodomenico(a)gmail.com are
The quilt patch titled
Subject: zsmalloc: move LRU update from zs_map_object() to zs_malloc()
has been removed from the -mm tree. Its filename was
zsmalloc-move-lru-update-from-zs_map_object-to-zs_malloc.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Nhat Pham <nphamcs(a)gmail.com>
Subject: zsmalloc: move LRU update from zs_map_object() to zs_malloc()
Date: Fri, 5 May 2023 11:50:54 -0700
Under memory pressure, we sometimes observe the following crash:
[ 5694.832838] ------------[ cut here ]------------
[ 5694.842093] list_del corruption, ffff888014b6a448->next is LIST_POISON1 (dead000000000100)
[ 5694.858677] WARNING: CPU: 33 PID: 418824 at lib/list_debug.c:47 __list_del_entry_valid+0x42/0x80
[ 5694.961820] CPU: 33 PID: 418824 Comm: fuse_counters.s Kdump: loaded Tainted: G S 5.19.0-0_fbk3_rc3_hoangnhatpzsdynshrv41_10870_g85a9558a25de #1
[ 5694.990194] Hardware name: Wiwynn Twin Lakes MP/Twin Lakes Passive MP, BIOS YMM16 05/24/2021
[ 5695.007072] RIP: 0010:__list_del_entry_valid+0x42/0x80
[ 5695.017351] Code: 08 48 83 c2 22 48 39 d0 74 24 48 8b 10 48 39 f2 75 2c 48 8b 51 08 b0 01 48 39 f2 75 34 c3 48 c7 c7 55 d7 78 82 e8 4e 45 3b 00 <0f> 0b eb 31 48 c7 c7 27 a8 70 82 e8 3e 45 3b 00 0f 0b eb 21 48 c7
[ 5695.054919] RSP: 0018:ffffc90027aef4f0 EFLAGS: 00010246
[ 5695.065366] RAX: 41fe484987275300 RBX: ffff888008988180 RCX: 0000000000000000
[ 5695.079636] RDX: ffff88886006c280 RSI: ffff888860060480 RDI: ffff888860060480
[ 5695.093904] RBP: 0000000000000002 R08: 0000000000000000 R09: ffffc90027aef370
[ 5695.108175] R10: 0000000000000000 R11: ffffffff82fdf1c0 R12: 0000000010000002
[ 5695.122447] R13: ffff888014b6a448 R14: ffff888014b6a420 R15: 00000000138dc240
[ 5695.136717] FS: 00007f23a7d3f740(0000) GS:ffff888860040000(0000) knlGS:0000000000000000
[ 5695.152899] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5695.164388] CR2: 0000560ceaab6ac0 CR3: 000000001c06c001 CR4: 00000000007706e0
[ 5695.178659] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 5695.192927] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 5695.207197] PKRU: 55555554
[ 5695.212602] Call Trace:
[ 5695.217486] <TASK>
[ 5695.221674] zs_map_object+0x91/0x270
[ 5695.229000] zswap_frontswap_store+0x33d/0x870
[ 5695.237885] ? do_raw_spin_lock+0x5d/0xa0
[ 5695.245899] __frontswap_store+0x51/0xb0
[ 5695.253742] swap_writepage+0x3c/0x60
[ 5695.261063] shrink_page_list+0x738/0x1230
[ 5695.269255] shrink_lruvec+0x5ec/0xcd0
[ 5695.276749] ? shrink_slab+0x187/0x5f0
[ 5695.284240] ? mem_cgroup_iter+0x6e/0x120
[ 5695.292255] shrink_node+0x293/0x7b0
[ 5695.299402] do_try_to_free_pages+0xea/0x550
[ 5695.307940] try_to_free_pages+0x19a/0x490
[ 5695.316126] __folio_alloc+0x19ff/0x3e40
[ 5695.323971] ? __filemap_get_folio+0x8a/0x4e0
[ 5695.332681] ? walk_component+0x2a8/0xb50
[ 5695.340697] ? generic_permission+0xda/0x2a0
[ 5695.349231] ? __filemap_get_folio+0x8a/0x4e0
[ 5695.357940] ? walk_component+0x2a8/0xb50
[ 5695.365955] vma_alloc_folio+0x10e/0x570
[ 5695.373796] ? walk_component+0x52/0xb50
[ 5695.381634] wp_page_copy+0x38c/0xc10
[ 5695.388953] ? filename_lookup+0x378/0xbc0
[ 5695.397140] handle_mm_fault+0x87f/0x1800
[ 5695.405157] do_user_addr_fault+0x1bd/0x570
[ 5695.413520] exc_page_fault+0x5d/0x110
[ 5695.421017] asm_exc_page_fault+0x22/0x30
After some investigation, I have found the following issue: unlike other
zswap backends, zsmalloc performs the LRU list update at the object
mapping time, rather than when the slot for the object is allocated.
This deviation was discussed and agreed upon during the review process
of the zsmalloc writeback patch series:
https://lore.kernel.org/lkml/Y3flcAXNxxrvy3ZH@cmpxchg.org/
Unfortunately, this introduces a subtle bug that occurs when there is a
concurrent store and reclaim, which interleave as follows:
zswap_frontswap_store() shrink_worker()
zs_malloc() zs_zpool_shrink()
spin_lock(&pool->lock) zs_reclaim_page()
zspage = find_get_zspage()
spin_unlock(&pool->lock)
spin_lock(&pool->lock)
zspage = list_first_entry(&pool->lru)
list_del(&zspage->lru)
zspage->lru.next = LIST_POISON1
zspage->lru.prev = LIST_POISON2
spin_unlock(&pool->lock)
zs_map_object()
spin_lock(&pool->lock)
if (!list_empty(&zspage->lru))
list_del(&zspage->lru)
CHECK_DATA_CORRUPTION(next == LIST_POISON1) /* BOOM */
With the current upstream code, this issue rarely happens. zswap only
triggers writeback when the pool is already full, at which point all
further store attempts are short-circuited. This creates an implicit
pseudo-serialization between reclaim and store. I am working on a new
zswap shrinking mechanism, which makes interleaving reclaim and store
more likely, exposing this bug.
zbud and z3fold do not have this problem, because they perform the LRU
list update in the alloc function, while still holding the pool's lock.
This patch fixes the aforementioned bug by moving the LRU update back to
zs_malloc(), analogous to zbud and z3fold.
Link: https://lkml.kernel.org/r/20230505185054.2417128-1-nphamcs@gmail.com
Fixes: 64f768c6b32e ("zsmalloc: add a LRU to zs_pool to keep track of zspages in LRU order")
Signed-off-by: Nhat Pham <nphamcs(a)gmail.com>
Suggested-by: Johannes Weiner <hannes(a)cmpxchg.org>
Acked-by: Johannes Weiner <hannes(a)cmpxchg.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky(a)chromium.org>
Acked-by: Minchan Kim <minchan(a)kernel.org>
Cc: Dan Streetman <ddstreet(a)ieee.org>
Cc: Nitin Gupta <ngupta(a)vflare.org>
Cc: Seth Jennings <sjenning(a)redhat.com>
Cc: Vitaly Wool <vitaly.wool(a)konsulko.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/zsmalloc.c | 36 +++++++++---------------------------
1 file changed, 9 insertions(+), 27 deletions(-)
--- a/mm/zsmalloc.c~zsmalloc-move-lru-update-from-zs_map_object-to-zs_malloc
+++ a/mm/zsmalloc.c
@@ -1331,31 +1331,6 @@ void *zs_map_object(struct zs_pool *pool
obj_to_location(obj, &page, &obj_idx);
zspage = get_zspage(page);
-#ifdef CONFIG_ZPOOL
- /*
- * Move the zspage to front of pool's LRU.
- *
- * Note that this is swap-specific, so by definition there are no ongoing
- * accesses to the memory while the page is swapped out that would make
- * it "hot". A new entry is hot, then ages to the tail until it gets either
- * written back or swaps back in.
- *
- * Furthermore, map is also called during writeback. We must not put an
- * isolated page on the LRU mid-reclaim.
- *
- * As a result, only update the LRU when the page is mapped for write
- * when it's first instantiated.
- *
- * This is a deviation from the other backends, which perform this update
- * in the allocation function (zbud_alloc, z3fold_alloc).
- */
- if (mm == ZS_MM_WO) {
- if (!list_empty(&zspage->lru))
- list_del(&zspage->lru);
- list_add(&zspage->lru, &pool->lru);
- }
-#endif
-
/*
* migration cannot move any zpages in this zspage. Here, pool->lock
* is too heavy since callers would take some time until they calls
@@ -1525,9 +1500,8 @@ unsigned long zs_malloc(struct zs_pool *
fix_fullness_group(class, zspage);
record_obj(handle, obj);
class_stat_inc(class, ZS_OBJS_INUSE, 1);
- spin_unlock(&pool->lock);
- return handle;
+ goto out;
}
spin_unlock(&pool->lock);
@@ -1550,6 +1524,14 @@ unsigned long zs_malloc(struct zs_pool *
/* We completely set up zspage so mark them as movable */
SetZsPageMovable(pool, zspage);
+out:
+#ifdef CONFIG_ZPOOL
+ /* Add/move zspage to beginning of LRU */
+ if (!list_empty(&zspage->lru))
+ list_del(&zspage->lru);
+ list_add(&zspage->lru, &pool->lru);
+#endif
+
spin_unlock(&pool->lock);
return handle;
_
Patches currently in -mm which might be from nphamcs(a)gmail.com are
workingset-refactor-lru-refault-to-expose-refault-recency-check.patch
cachestat-implement-cachestat-syscall.patch
cachestat-implement-cachestat-syscall-fix.patch
cachestat-wire-up-cachestat-for-other-architectures.patch
cachestat-wire-up-cachestat-for-other-architectures-fix.patch
selftests-add-selftests-for-cachestat.patch
The quilt patch titled
Subject: maple_tree: make maple state reusable after mas_empty_area()
has been removed from the -mm tree. Its filename was
maple_tree-make-maple-state-reusable-after-mas_empty_area.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Peng Zhang <zhangpeng.00(a)bytedance.com>
Subject: maple_tree: make maple state reusable after mas_empty_area()
Date: Fri, 5 May 2023 22:58:29 +0800
Make mas->min and mas->max point to a node range instead of a leaf entry
range. This allows mas to still be usable after mas_empty_area() returns.
Users would get unexpected results from other operations on the maple
state after calling the affected function.
For example, x86 MAP_32BIT mmap() acts as if there is no suitable gap when
there should be one.
Link: https://lkml.kernel.org/r/20230505145829.74574-1-zhangpeng.00@bytedance.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <zhangpeng.00(a)bytedance.com>
Reported-by: "Edgecombe, Rick P" <rick.p.edgecombe(a)intel.com>
Reported-by: Tad <support(a)spotco.us>
Reported-by: Michael Keyes <mgkeyes(a)vigovproductions.net>
Link: https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.c…
Link: https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.c…
Reviewed-by: Liam R. Howlett <Liam.Howlett(a)oracle.com>
Tested-by: Rick Edgecombe <rick.p.edgecombe(a)intel.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
lib/maple_tree.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
--- a/lib/maple_tree.c~maple_tree-make-maple-state-reusable-after-mas_empty_area
+++ a/lib/maple_tree.c
@@ -5317,15 +5317,9 @@ int mas_empty_area(struct ma_state *mas,
mt = mte_node_type(mas->node);
pivots = ma_pivots(mas_mn(mas), mt);
- if (offset)
- mas->min = pivots[offset - 1] + 1;
-
- if (offset < mt_pivots[mt])
- mas->max = pivots[offset];
-
- if (mas->index < mas->min)
- mas->index = mas->min;
-
+ min = mas_safe_min(mas, pivots, offset);
+ if (mas->index < min)
+ mas->index = min;
mas->last = mas->index + size - 1;
return 0;
}
_
Patches currently in -mm which might be from zhangpeng.00(a)bytedance.com are
maple_tree-fix-potential-out-of-bounds-access-in-mas_wr_end_piv.patch
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: ce0b15d11ad837fbacc5356941712218e38a0a83
Gitweb: https://git.kernel.org/tip/ce0b15d11ad837fbacc5356941712218e38a0a83
Author: Dave Hansen <dave.hansen(a)linux.intel.com>
AuthorDate: Tue, 16 May 2023 12:24:25 -07:00
Committer: Dave Hansen <dave.hansen(a)linux.intel.com>
CommitterDate: Wed, 17 May 2023 08:55:02 -07:00
x86/mm: Avoid incomplete Global INVLPG flushes
The INVLPG instruction is used to invalidate TLB entries for a
specified virtual address. When PCIDs are enabled, INVLPG is supposed
to invalidate TLB entries for the specified address for both the
current PCID *and* Global entries. (Note: Only kernel mappings set
Global=1.)
Unfortunately, some INVLPG implementations can leave Global
translations unflushed when PCIDs are enabled.
As a workaround, never enable PCIDs on affected processors.
I expect there to eventually be microcode mitigations to replace this
software workaround. However, the exact version numbers where that
will happen are not known today. Once the version numbers are set in
stone, the processor list can be tweaked to only disable PCIDs on
affected processors with affected microcode.
Note: if anyone wants a quick fix that doesn't require patching, just
stick 'nopcid' on your kernel command-line.
Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
---
arch/x86/mm/init.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 3cdac0f..8192452 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -9,6 +9,7 @@
#include <linux/sched/task.h>
#include <asm/set_memory.h>
+#include <asm/cpu_device_id.h>
#include <asm/e820/api.h>
#include <asm/init.h>
#include <asm/page.h>
@@ -261,6 +262,24 @@ static void __init probe_page_size_mask(void)
}
}
+#define INTEL_MATCH(_model) { .vendor = X86_VENDOR_INTEL, \
+ .family = 6, \
+ .model = _model, \
+ }
+/*
+ * INVLPG may not properly flush Global entries
+ * on these CPUs when PCIDs are enabled.
+ */
+static const struct x86_cpu_id invlpg_miss_ids[] = {
+ INTEL_MATCH(INTEL_FAM6_ALDERLAKE ),
+ INTEL_MATCH(INTEL_FAM6_ALDERLAKE_L ),
+ INTEL_MATCH(INTEL_FAM6_ALDERLAKE_N ),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE ),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_P),
+ INTEL_MATCH(INTEL_FAM6_RAPTORLAKE_S),
+ {}
+};
+
static void setup_pcid(void)
{
if (!IS_ENABLED(CONFIG_X86_64))
@@ -269,6 +288,12 @@ static void setup_pcid(void)
if (!boot_cpu_has(X86_FEATURE_PCID))
return;
+ if (x86_match_cpu(invlpg_miss_ids)) {
+ pr_info("Incomplete global flushes, disabling PCID");
+ setup_clear_cpu_cap(X86_FEATURE_PCID);
+ return;
+ }
+
if (boot_cpu_has(X86_FEATURE_PGE)) {
/*
* This can't be cr4_set_bits_and_update_boot() -- the