CVE-2024-56744

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to avoid potential deadlock in f2fsrecordstop_reason()

syzbot reports deadlock issue of f2fs as below:

====================================================== WARNING: possible circular locking dependency detected

6.12.0-rc3-syzkaller-00087-gc964ced77262 #0 Not tainted

kswapd0/79 is trying to acquire lock: ffff888011824088 (&sbi->sblock){++++}-{3:3}, at: f2fsdownwrite fs/f2fs/f2fs.h:2199 [inline] ffff888011824088 (&sbi->sblock){++++}-{3:3}, at: f2fsrecordstop_reason+0x52/0x1d0 fs/f2fs/super.c:4068

but task is already holding lock: ffff88804bd92610 (sbinternal#2){.+.+}-{0:0}, at: f2fsevict_inode+0x662/0x15c0 fs/f2fs/inode.c:842

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (sbinternal#2){.+.+}-{0:0}: lockacquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 percpudownread include/linux/percpu-rwsem.h:51 [inline] _sbstartwrite include/linux/fs.h:1716 [inline] sbstartintwrite+0x4d/0x1c0 include/linux/fs.h:1899 f2fsevictinode+0x662/0x15c0 fs/f2fs/inode.c:842 evict+0x4e8/0x9b0 fs/inode.c:725 f2fsevictinode+0x1a4/0x15c0 fs/f2fs/inode.c:807 evict+0x4e8/0x9b0 fs/inode.c:725 disposelist fs/inode.c:774 [inline] pruneicachesb+0x239/0x2f0 fs/inode.c:963 supercachescan+0x38c/0x4b0 fs/super.c:223 doshrinkslab+0x701/0x1160 mm/shrinker.c:435 shrinkslab+0x1093/0x14d0 mm/shrinker.c:662 shrinkone+0x43b/0x850 mm/vmscan.c:4818 shrinkmany mm/vmscan.c:4879 [inline] lrugenshrinknode mm/vmscan.c:4957 [inline] shrinknode+0x3799/0x3de0 mm/vmscan.c:5937 kswapdshrinknode mm/vmscan.c:6765 [inline] balancepgdat mm/vmscan.c:6957 [inline] kswapd+0x1ca3/0x3700 mm/vmscan.c:7226 kthread+0x2f0/0x390 kernel/kthread.c:389 retfromfork+0x4b/0x80 arch/x86/kernel/process.c:147 retfromforkasm+0x1a/0x30 arch/x86/entry/entry64.S:244

-> #1 (fsreclaim){+.+.}-{0:0}: lockacquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 _fsreclaimacquire mm/pagealloc.c:3834 [inline] fsreclaimacquire+0x88/0x130 mm/pagealloc.c:3848 mightalloc include/linux/sched/mm.h:318 [inline] prepareallocpages+0x147/0x5b0 mm/pagealloc.c:4493 _allocpagesnoprof+0x16f/0x710 mm/pagealloc.c:4722 allocpagesmpolnoprof+0x3e8/0x680 mm/mempolicy.c:2265 allocpagesnoprof mm/mempolicy.c:2345 [inline] folioallocnoprof+0x128/0x180 mm/mempolicy.c:2352 filemapallocfolionoprof+0xdf/0x500 mm/filemap.c:1010 doreadcachefolio+0x2eb/0x850 mm/filemap.c:3787 readmappingfolio include/linux/pagemap.h:1011 [inline] f2fscommitsuper+0x3c0/0x7d0 fs/f2fs/super.c:4032 f2fsrecordstopreason+0x13b/0x1d0 fs/f2fs/super.c:4079 f2fshandlecriticalerror+0x2ac/0x5c0 fs/f2fs/super.c:4174 f2fswriteinode+0x35f/0x4d0 fs/f2fs/inode.c:785 writeinode fs/fs-writeback.c:1503 [inline] _writebacksingleinode+0x711/0x10d0 fs/fs-writeback.c:1723 writebacksingleinode+0x1f3/0x660 fs/fs-writeback.c:1779 syncinodemetadata+0xc4/0x120 fs/fs-writeback.c:2849 f2fsreleasefile+0xa8/0x100 fs/f2fs/file.c:1941 _fput+0x23f/0x880 fs/filetable.c:431 taskworkrun+0x24f/0x310 kernel/taskwork.c:228 resumeusermodework include/linux/resumeusermode.h:50 [inline] exittousermodeloop kernel/entry/common.c:114 [inline] exittousermodeprepare include/linux/entry-common.h:328 [inline] _syscallexittousermodework kernel/entry/common.c:207 [inline] syscallexittousermode+0x168/0x370 kernel/entry/common.c:218 dosyscall64+0x100/0x230 arch/x86/entry/common.c:89 entrySYSCALL64afterhwframe+0x77/0x7f

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