KASAN: use-after-free Read in f2fs_inode_dirtied

Status: auto-obsoleted due to no activity on 2025/11/18 10:06
Reported-by: syzbot+306cd88a5aa727bfcace@syzkaller.appspotmail.com
First crash: 422d, last: 372d
Fix bisection: fixed by (bisect log) :
commit 4dcd830c420f2190ae32f03626039fde7b57b2ad
Author: Chao Yu <chao@kernel.org>
Date: Tue Jul 8 09:53:39 2025 +0000

  f2fs: fix to avoid UAF in f2fs_sync_inode_meta()

  
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2025/09/20 20:35 11m retest repro android13-5.10-lts no crash log
2025/09/20 20:35 14m retest repro android13-5.10-lts no crash log
2025/07/10 21:05 6m retest repro android13-5.10-lts report log
2025/07/10 21:05 5m retest repro android13-5.10-lts report log
2025/07/10 21:05 8m retest repro android13-5.10-lts report log
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2025/09/16 19:13 4h04m bisect fix android13-5.10-lts OK (1) job log
2025/08/10 09:21 44m bisect fix android13-5.10-lts OK (0) job log log

Sample crash report:
RDX: 00007fff1091aef0 RSI: 00007fff1091af80 RDI: 00007fff1091af80
RBP: 00007fff1091af80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff1091c070
R13: 000055558933f700 R14: 0000000000000001 R15: 431bde82d7b634db
---[ end trace 7f1cee6c2f8e56f1 ]---
==================================================================
BUG: KASAN: use-after-free in __list_add_valid+0x6b/0xf0 lib/list_debug.c:30
Read of size 8 at addr ffff888120c06440 by task syz-executor290/282

CPU: 1 PID: 282 Comm: syz-executor290 Tainted: G        W         5.10.238-syzkaller-00008-g59e9a7228857 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 __list_add_valid+0x6b/0xf0 lib/list_debug.c:30
 __list_add include/linux/list.h:67 [inline]
 list_add_tail include/linux/list.h:100 [inline]
 f2fs_inode_dirtied+0x199/0x2a0 fs/f2fs/super.c:1476
 f2fs_mark_inode_dirty_sync+0xfa/0x140 fs/f2fs/inode.c:33
 f2fs_i_links_write fs/f2fs/f2fs.h:3026 [inline]
 f2fs_drop_nlink+0x155/0x3c0 fs/f2fs/dir.c:921
 f2fs_delete_entry+0x9d5/0xb30 fs/f2fs/dir.c:988
 f2fs_unlink+0x422/0x800 fs/f2fs/namei.c:630
 vfs_unlink+0x321/0x540 fs/namei.c:3971
 do_unlinkat+0x2e9/0x670 fs/namei.c:4036
 __do_sys_unlink fs/namei.c:4082 [inline]
 __se_sys_unlink fs/namei.c:4080 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4080
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fabcdf58b97
Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff1091aec8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fabcdf58b97
RDX: 00007fff1091aef0 RSI: 00007fff1091af80 RDI: 00007fff1091af80
RBP: 00007fff1091af80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fff1091c070
R13: 000055558933f700 R14: 0000000000000001 R15: 431bde82d7b634db

Allocated by task 284:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2779 [inline]
 f2fs_alloc_inode+0x26/0x410 fs/f2fs/super.c:1373
 alloc_inode fs/inode.c:233 [inline]
 iget_locked+0x146/0x7d0 fs/inode.c:1275
 f2fs_iget+0x55/0x4dc0 fs/f2fs/inode.c:498
 f2fs_lookup+0x3ee/0xce0 fs/f2fs/namei.c:544
 lookup_open fs/namei.c:3226 [inline]
 open_last_lookups fs/namei.c:3317 [inline]
 path_openat+0x1127/0x3160 fs/namei.c:3506
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536
 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217
 do_sys_open fs/open.c:1233 [inline]
 __do_sys_openat fs/open.c:1249 [inline]
 __se_sys_openat fs/open.c:1244 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1244
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 12:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1595 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3219
 f2fs_free_inode+0x24/0x30 fs/f2fs/super.c:1528
 i_callback+0x4c/0x70 fs/inode.c:222
 rcu_do_batch+0x4df/0xa80 kernel/rcu/tree.c:2494
 rcu_core+0x55f/0xd60 kernel/rcu/tree.c:2735
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748
 __do_softirq+0x255/0x563 kernel/softirq.c:309

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x105/0x1040 kernel/rcu/tree.c:3050
 destroy_inode fs/inode.c:288 [inline]
 evict+0x857/0x910 fs/inode.c:629
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 do_unlinkat+0x33f/0x670 fs/namei.c:4042
 __do_sys_unlink fs/namei.c:4082 [inline]
 __se_sys_unlink fs/namei.c:4080 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4080
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888120c06090
 which belongs to the cache f2fs_inode_cache of size 1520
The buggy address is located 944 bytes inside of
 1520-byte region [ffff888120c06090, ffff888120c06680)
The buggy address belongs to the page:
page:ffffea0004830000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x120c00
head:ffffea0004830000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff8881029d3800
raw: 0000000000000000 0000000080130013 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE), pid 284, ts 24307849543, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5357
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2779 [inline]
 f2fs_alloc_inode+0x26/0x410 fs/f2fs/super.c:1373
 alloc_inode fs/inode.c:233 [inline]
 iget_locked+0x146/0x7d0 fs/inode.c:1275
 f2fs_iget+0x55/0x4dc0 fs/f2fs/inode.c:498
 f2fs_fill_super+0x39f0/0x6c70 fs/f2fs/super.c:4193
 mount_bdev+0x28b/0x3a0 fs/super.c:1442
 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4548
 legacy_get_tree+0xed/0x190 fs/fs_context.c:593
 vfs_get_tree+0x89/0x260 fs/super.c:1572
 do_new_mount+0x25a/0xa20 fs/namespace.c:2915
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888120c06300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888120c06380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888120c06400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888120c06480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888120c06500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/25 20:50 android13-5.10-lts 59e9a7228857 26d77996 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in f2fs_inode_dirtied
2025/06/25 20:06 android13-5.10-lts 59e9a7228857 26d77996 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in f2fs_inode_dirtied
2025/06/21 08:49 android13-5.10-lts d76d4cd0623a d6cdfb8a .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in f2fs_inode_dirtied
* Struck through repros no longer work on HEAD.