syzbot

 sign-in | mailing list | source | docs
🐞 Open [101]
🐞 Fixed [70]
🐞 Invalid [204]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

KASAN: use-after-free Read in __ext4_iget

Status: upstream: reported C repro on 2025/03/08 14:28
Reported-by: syzbot+3a99b74b9292ab1dacb8@syzkaller.appspotmail.com
First crash: 620d, last: 4h29m
▶ ▼ Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in __ext4_iget 2 178d 220d 0/3 auto-obsoleted due to no activity on 2024/12/21 07:26
linux-5.15 KASAN: use-after-free Read in __ext4_iget 21 5d19h 403d 0/3 upstream: reported on 2024/01/31 03:06
upstream KASAN: slab-use-after-free Read in __ext4_iget fs reiserfs 278 404d 641d 0/28 auto-obsoleted due to no activity on 2024/04/09 13:42
android-5-15 KASAN: use-after-free Read in __ext4_iget origin:lts syz 244 1d00h 620d 0/2 premoderation: reported syz repro on 2023/06/28 10:27
linux-5.15 KASAN: slab-out-of-bounds Read in __ext4_iget 6 508d 551d 0/3 auto-obsoleted due to no activity on 2024/01/25 22:09
android-54 KASAN: use-after-free Read in __ext4_iget 13 380d 587d 0/2 auto-obsoleted due to no activity on 2024/05/22 19:07
android-54 KASAN: use-after-free Read in __ext4_iget (2) 4 263d 281d 0/2 auto-obsoleted due to no activity on 2024/09/17 10:19
linux-6.1 KASAN: slab-out-of-bounds Read in __ext4_iget 14 342d 598d 0/3 auto-obsoleted due to no activity on 2024/07/09 19:10
linux-6.1 KASAN: slab-out-of-bounds Read in __ext4_iget (2) 1 35d 35d 0/3 upstream: reported on 2025/02/01 20:39
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/08/17 15:33 54m retest repro android13-5.10-lts OK log
2024/04/09 21:26 27m retest repro android13-5.10-lts report log
2023/12/31 14:54 14m retest repro android13-5.10-lts report log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2024/06/08 14:03 1h27m bisect fix android13-5.10-lts OK (0) job log log

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __ext4_iget+0x3a0/0x41f0 fs/ext4/inode.c:4766
Read of size 8 at addr ffff888122438b98 by task syz-executor274/564

CPU: 1 PID: 564 Comm: syz-executor274 Not tainted 5.10.234-syzkaller-00023-g3f5f2283d684 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 __ext4_iget+0x3a0/0x41f0 fs/ext4/inode.c:4766
 ext4_quota_enable fs/ext4/super.c:6423 [inline]
 ext4_enable_quotas+0x56f/0x9f0 fs/ext4/super.c:6459
 ext4_fill_super+0x86dc/0x9150 fs/ext4/super.c:5060
 mount_bdev+0x262/0x370 fs/super.c:1442
 ext4_mount+0x34/0x40 fs/ext4/super.c:6638
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593
 vfs_get_tree+0x88/0x290 fs/super.c:1572
 do_new_mount+0x2ba/0xb30 fs/namespace.c:2917
 path_mount+0x56f/0xcb0 fs/namespace.c:3247
 do_mount fs/namespace.c:3260 [inline]
 __do_sys_mount fs/namespace.c:3468 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3445
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3445
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7faabcab17ea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 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:00007fff21021b48 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff21021ba0 RCX: 00007faabcab17ea
RDX: 0000400000000180 RSI: 0000400000000000 RDI: 00007fff21021ba0
RBP: 0000400000000000 R08: 00007fff21021be0 R09: 00000000000004fb
R10: 000000000021081e R11: 0000000000000202 R12: 0000400000000180
R13: 00007fff21021be0 R14: 0000000000000501 R15: 00004000000001c0

Allocated by task 322:
 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+0xb1/0xe0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x61/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x168/0x2e0 mm/slub.c:2960
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2779 [inline]
 f2fs_alloc_inode+0x26/0x420 fs/f2fs/super.c:1373
 alloc_inode fs/inode.c:233 [inline]
 iget_locked+0x14f/0x870 fs/inode.c:1275
 f2fs_iget+0x55/0x50a0 fs/f2fs/inode.c:498
 f2fs_fill_super+0x63b6/0x7d90 fs/f2fs/super.c:4301
 mount_bdev+0x262/0x370 fs/super.c:1442
 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4548
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593
 vfs_get_tree+0x88/0x290 fs/super.c:1572
 do_new_mount+0x2ba/0xb30 fs/namespace.c:2917
 path_mount+0x56f/0xcb0 fs/namespace.c:3247
 do_mount fs/namespace.c:3260 [inline]
 __do_sys_mount fs/namespace.c:3468 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3445
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3445
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd3/0x100 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+0x135/0x11f0 kernel/rcu/tree.c:3050
 destroy_inode fs/inode.c:288 [inline]
 evict+0x8e8/0x9c0 fs/inode.c:629
 iput_final fs/inode.c:1736 [inline]
 iput+0x632/0x7e0 fs/inode.c:1762
 f2fs_fill_super+0x66c7/0x7d90 fs/f2fs/super.c:4484
 mount_bdev+0x262/0x370 fs/super.c:1442
 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4548
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593
 vfs_get_tree+0x88/0x290 fs/super.c:1572
 do_new_mount+0x2ba/0xb30 fs/namespace.c:2917
 path_mount+0x56f/0xcb0 fs/namespace.c:3247
 do_mount fs/namespace.c:3260 [inline]
 __do_sys_mount fs/namespace.c:3468 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3445
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3445
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888122438670
 which belongs to the cache f2fs_inode_cache of size 1520
The buggy address is located 1320 bytes inside of
 1520-byte region [ffff888122438670, ffff888122438c60)
The buggy address belongs to the page:
page:ffffea0004890e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88812243ed70 pfn:0x122438
head:ffffea0004890e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 0000000000000000 0000000100000001 ffff8881029afc80
raw: ffff88812243ed70 000000008013000f 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 295, ts 21183581206, 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+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x80/0x400 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x302/0x4b0 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+0x1b9/0x2e0 mm/slub.c:2960
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2779 [inline]
 f2fs_alloc_inode+0x26/0x420 fs/f2fs/super.c:1373
 alloc_inode fs/inode.c:233 [inline]
 iget_locked+0x14f/0x870 fs/inode.c:1275
 f2fs_iget+0x55/0x50a0 fs/f2fs/inode.c:498
 f2fs_fill_super+0x4c57/0x7d90 fs/f2fs/super.c:4193
 mount_bdev+0x262/0x370 fs/super.c:1442
 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4548
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593
 vfs_get_tree+0x88/0x290 fs/super.c:1572
 do_new_mount+0x2ba/0xb30 fs/namespace.c:2917
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888122438a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888122438b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888122438b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888122438c00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888122438c80: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00
==================================================================
EXT4-fs warning (device loop0): ext4_enable_quotas:6467: Failed to enable quota tracking (type=0, err=-13, ino=3). Please run e2fsck to fix.
EXT4-fs (loop0): mount failed

Crashes (192):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/08 14:18 android13-5.10-lts 3f5f2283d684 7e3bd60d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (clean fs)] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2023/11/03 05:57 android13-5.10-lts d30b996835c0 c4ac074c .config strace log report syz [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/03/08 21:52 android13-5.10-lts 3f5f2283d684 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/03/08 10:19 android13-5.10-lts 3f5f2283d684 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/03/05 15:40 android13-5.10-lts 3f5f2283d684 60f5d8d9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/03/02 17:26 android13-5.10-lts 3f5f2283d684 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/03/02 00:32 android13-5.10-lts 3f5f2283d684 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/03/01 08:17 android13-5.10-lts 3f5f2283d684 67cf5345 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/27 10:30 android13-5.10-lts 3f5f2283d684 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/26 10:35 android13-5.10-lts 3f5f2283d684 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/24 10:08 android13-5.10-lts 3f5f2283d684 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/23 13:03 android13-5.10-lts 3f5f2283d684 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/21 21:10 android13-5.10-lts 6686f2996d23 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/19 13:31 android13-5.10-lts 6686f2996d23 9a14138f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/17 21:04 android13-5.10-lts 6686f2996d23 429ea007 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/15 03:16 android13-5.10-lts 6686f2996d23 1022af74 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/14 19:54 android13-5.10-lts 6686f2996d23 1022af74 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/14 06:21 android13-5.10-lts 6686f2996d23 d9a046cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/10 16:55 android13-5.10-lts 6686f2996d23 43f51a00 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/10 11:15 android13-5.10-lts 6686f2996d23 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/07 21:57 android13-5.10-lts 6686f2996d23 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/02/02 05:08 android13-5.10-lts fbe98d68b6b3 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/30 15:43 android13-5.10-lts fbe98d68b6b3 4c6ac32f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/27 16:32 android13-5.10-lts fbe98d68b6b3 d99a33ad .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/26 03:28 android13-5.10-lts fbe98d68b6b3 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/25 06:59 android13-5.10-lts fbe98d68b6b3 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/22 19:25 android13-5.10-lts fbe98d68b6b3 a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/22 00:58 android13-5.10-lts fbe98d68b6b3 da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/19 09:47 android13-5.10-lts fbe98d68b6b3 f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/16 22:32 android13-5.10-lts fbe98d68b6b3 f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/16 13:49 android13-5.10-lts fbe98d68b6b3 f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/13 22:42 android13-5.10-lts 49e8ba0a684f 249ceea9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/11 19:10 android13-5.10-lts 49e8ba0a684f 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/11 02:30 android13-5.10-lts 49e8ba0a684f 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/09 01:04 android13-5.10-lts 49e8ba0a684f f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/07 19:17 android13-5.10-lts 49e8ba0a684f f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/03 03:51 android13-5.10-lts 49e8ba0a684f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/01 14:26 android13-5.10-lts 49e8ba0a684f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/01/01 07:35 android13-5.10-lts 49e8ba0a684f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2024/12/30 11:57 android13-5.10-lts 49e8ba0a684f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2024/12/28 07:12 android13-5.10-lts 4055d754db6f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2024/12/27 13:13 android13-5.10-lts 4055d754db6f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2024/12/25 21:25 android13-5.10-lts 4055d754db6f 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2024/12/25 01:03 android13-5.10-lts 4055d754db6f 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in __ext4_iget
2025/03/09 10:58 android13-5.10-lts 3f5f2283d684 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in __ext4_iget
2025/01/01 12:40 android13-5.10-lts 49e8ba0a684f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in __ext4_iget
* Struck through repros no longer work on HEAD.