[syzbot] [netfs?] KASAN: slab-use-after-free Write in __fscache_relinquish_cookie

syzbot
2024-02-02T09:46:29Z

Hello,

syzbot found the following issue on:

HEAD commit: 596764183be8 Add linux-next specific files for 20240129
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12643c47e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=584144ad19f381aa
dashboard link: https://syzkaller.appspot.com/bug?extid=a4c1a7875b2babd9e359
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17ed937fe80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17805467e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b647c038857b/disk-59676418.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/729e26c3ac55/vmlinux-59676418.xz
kernel image: https://storage.googleapis.com/syzbot-assets/15aa5e287059/bzImage-59676418.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a4c1a7875b2babd9e359@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: wild-memory-access in test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline]
BUG: KASAN: wild-memory-access in __fscache_relinquish_cookie+0x2a/0x620 fs/netfs/fscache_cookie.c:977
Write of size 8 at addr adacafaea9a8ac9a by task syz-executor410/9304

CPU: 0 PID: 9304 Comm: syz-executor410 Not tainted 6.8.0-rc1-next-20240129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
kasan_report+0xd9/0x110 mm/kasan/report.c:601
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline]
__fscache_relinquish_cookie+0x2a/0x620 fs/netfs/fscache_cookie.c:977
fscache_relinquish_cookie include/linux/fscache.h:308 [inline]
v9fs_evict_inode+0x102/0x150 fs/9p/vfs_inode.c:356
evict+0x2ed/0x6c0 fs/inode.c:666
iput_final fs/inode.c:1740 [inline]
iput.part.0+0x573/0x7c0 fs/inode.c:1766
iput+0x5c/0x80 fs/inode.c:1756
v9fs_fid_iget_dotl+0x1b4/0x260 fs/9p/vfs_inode_dotl.c:96
v9fs_get_inode_from_fid fs/9p/v9fs.h:230 [inline]
v9fs_mount+0x515/0xa90 fs/9p/vfs_super.c:142
legacy_get_tree+0x109/0x220 fs/fs_context.c:662
vfs_get_tree+0x8f/0x380 fs/super.c:1784
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__x64_sys_mount+0x297/0x320 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f0b9d2fb899
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe6ee450d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0b9d2fb899
RDX: 00000000200001c0 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000020000300 R09: 00007f0b9d200990
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe6ee450fc
R13: 00007ffe6ee45130 R14: 00007ffe6ee45110 R15: 0000000000001086
</TASK>
==================================================================

---
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