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author | yangerkun <yangerkun@huawei.com> | 2021-06-16 04:23:32 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-23 15:42:40 +0300 |
commit | 9e379da727a7a031be9b877cde7b9c34a0fb8306 (patch) | |
tree | e1d4b5d6a2af09263328c77fe3a222fd347953fe /mm/memory-failure.c | |
parent | 090b1bb928a91c6c402ebb067fb32a14f41f6951 (diff) | |
download | linux-9e379da727a7a031be9b877cde7b9c34a0fb8306.tar.xz |
mm/memory-failure: make sure wait for page writeback in memory_failure
[ Upstream commit e8675d291ac007e1c636870db880f837a9ea112a ]
Our syzkaller trigger the "BUG_ON(!list_empty(&inode->i_wb_list))" in
clear_inode:
kernel BUG at fs/inode.c:519!
Internal error: Oops - BUG: 0 [#1] SMP
Modules linked in:
Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7)
CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO)
pc : clear_inode+0x280/0x2a8
lr : clear_inode+0x280/0x2a8
Call trace:
clear_inode+0x280/0x2a8
ext4_clear_inode+0x38/0xe8
ext4_free_inode+0x130/0xc68
ext4_evict_inode+0xb20/0xcb8
evict+0x1a8/0x3c0
iput+0x344/0x460
do_unlinkat+0x260/0x410
__arm64_sys_unlinkat+0x6c/0xc0
el0_svc_common+0xdc/0x3b0
el0_svc_handler+0xf8/0x160
el0_svc+0x10/0x218
Kernel panic - not syncing: Fatal exception
A crash dump of this problem show that someone called __munlock_pagevec
to clear page LRU without lock_page: do_mmap -> mmap_region -> do_munmap
-> munlock_vma_pages_range -> __munlock_pagevec.
As a result memory_failure will call identify_page_state without
wait_on_page_writeback. And after truncate_error_page clear the mapping
of this page. end_page_writeback won't call sb_clear_inode_writeback to
clear inode->i_wb_list. That will trigger BUG_ON in clear_inode!
Fix it by checking PageWriteback too to help determine should we skip
wait_on_page_writeback.
Link: https://lkml.kernel.org/r/20210604084705.3729204-1-yangerkun@huawei.com
Fixes: 0bc1f8b0682c ("hwpoison: fix the handling path of the victimized page frame that belong to non-LRU")
Signed-off-by: yangerkun <yangerkun@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'mm/memory-failure.c')
-rw-r--r-- | mm/memory-failure.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2d7a667f8e60..25fb82320e3d 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1445,7 +1445,12 @@ int memory_failure(unsigned long pfn, int flags) return 0; } - if (!PageTransTail(p) && !PageLRU(p)) + /* + * __munlock_pagevec may clear a writeback page's LRU flag without + * page_lock. We need wait writeback completion for this page or it + * may trigger vfs BUG while evict inode. + */ + if (!PageTransTail(p) && !PageLRU(p) && !PageWriteback(p)) goto identify_page_state; /* |