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KASAN: use-after-free Read in __ext4_iget (3)

Status: upstream: reported C repro on 2025/03/13 17:21
Reported-by: syzbot+2e888c41f43fbd593d7c@syzkaller.appspotmail.com
First crash: 63d, last: 3d19h
▶ ▼ Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in __ext4_iget 2 210d 252d 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 28 5d02h 435d 0/3 upstream: reported on 2024/01/31 03:06
linux-6.1 KASAN: slab-out-of-bounds Read in __ext4_iget (2) 8 7d03h 68d 0/3 upstream: reported on 2025/02/01 20:39
upstream KASAN: slab-use-after-free Read in __ext4_iget fs reiserfs 278 436d 673d 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 C 296 9h49m 9d03h 0/2 upstream: reported C repro on 2025/04/01 19:00
linux-5.15 KASAN: slab-out-of-bounds Read in __ext4_iget 6 540d 584d 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 413d 620d 0/2 auto-obsoleted due to no activity on 2024/05/22 19:07
android-5-10 KASAN: use-after-free Read in __ext4_iget C 225 15h07m 33d 0/2 upstream: reported C repro on 2025/03/08 14:28
android-54 KASAN: use-after-free Read in __ext4_iget (2) 4 295d 313d 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 375d 630d 0/3 auto-obsoleted due to no activity on 2024/07/09 19:10

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:4953 [inline]
BUG: KASAN: use-after-free in __ext4_iget+0x384/0x4330 fs/ext4/inode.c:5001
Read of size 8 at addr ffff8881dcf92ad0 by task syz-executor300/634

CPU: 1 PID: 634 Comm: syz-executor300 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #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+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 check_igot_inode fs/ext4/inode.c:4953 [inline]
 __ext4_iget+0x384/0x4330 fs/ext4/inode.c:5001
 ext4_quota_enable fs/ext4/super.c:6056 [inline]
 ext4_enable_quotas+0x528/0x940 fs/ext4/super.c:6092
 ext4_fill_super+0x84f0/0x8d90 fs/ext4/super.c:4708
 mount_bdev+0x267/0x370 fs/super.c:1428
 legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
 vfs_get_tree+0x85/0x260 fs/super.c:1558
 do_new_mount+0x292/0x570 fs/namespace.c:2850
 do_mount+0x688/0xe10 fs/namespace.c:3170
 ksys_mount+0xc2/0xf0 fs/namespace.c:3379
 __do_sys_mount fs/namespace.c:3393 [inline]
 __se_sys_mount fs/namespace.c:3390 [inline]
 __x64_sys_mount+0xb1/0xc0 fs/namespace.c:3390
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7fb955bc38da
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:00007ffdf3906f98 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdf3906ff0 RCX: 00007fb955bc38da
RDX: 0000400000000180 RSI: 0000400000000000 RDI: 00007ffdf3906ff0
RBP: 0000400000000000 R08: 00007ffdf3907030 R09: 00000000000004fb
R10: 000000000021081e R11: 0000000000000206 R12: 0000400000000180
R13: 00007ffdf3907030 R14: 0000000000000501 R15: 00004000000001c0

Allocated by task 450:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
 f2fs_alloc_inode+0x22/0x3c0 fs/f2fs/super.c:1241
 alloc_inode fs/inode.c:231 [inline]
 iget_locked+0x143/0x790 fs/inode.c:1273
 f2fs_iget+0x52/0x4cf0 fs/f2fs/inode.c:499
 f2fs_fill_super+0x6909/0x8330 fs/f2fs/super.c:4071
 mount_bdev+0x267/0x370 fs/super.c:1428
 legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
 vfs_get_tree+0x85/0x260 fs/super.c:1558
 do_new_mount+0x292/0x570 fs/namespace.c:2850
 do_mount+0x688/0xe10 fs/namespace.c:3170
 ksys_mount+0xc2/0xf0 fs/namespace.c:3379
 __do_sys_mount fs/namespace.c:3393 [inline]
 __se_sys_mount fs/namespace.c:3390 [inline]
 __x64_sys_mount+0xb1/0xc0 fs/namespace.c:3390
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 10:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
 rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292

The buggy address belongs to the object at ffff8881dcf92610
 which belongs to the cache f2fs_inode_cache of size 1264
The buggy address is located 1216 bytes inside of
 1264-byte region [ffff8881dcf92610, ffff8881dcf92b00)
The buggy address belongs to the page:
page:ffffea000773e400 refcount:1 mapcount:0 mapping:ffff8881f0fcc500 index:0xffff8881dcf90570 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 0000000000000000 0000000100000001 ffff8881f0fcc500
raw: ffff8881dcf90570 0000000080170011 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)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
 alloc_slab_page+0x39/0x3c0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x97/0x440 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x2fe/0x490 mm/slub.c:2667
 __slab_alloc+0x62/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
 f2fs_alloc_inode+0x22/0x3c0 fs/f2fs/super.c:1241
 alloc_inode fs/inode.c:231 [inline]
 iget_locked+0x143/0x790 fs/inode.c:1273
 f2fs_iget+0x52/0x4cf0 fs/f2fs/inode.c:499
 f2fs_fill_super+0x4d1b/0x8330 fs/f2fs/super.c:3963
 mount_bdev+0x267/0x370 fs/super.c:1428
 legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
 vfs_get_tree+0x85/0x260 fs/super.c:1558
 do_new_mount+0x292/0x570 fs/namespace.c:2850
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881dcf92980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881dcf92a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881dcf92a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff8881dcf92b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881dcf92b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
EXT4-fs warning (device loop2): ext4_enable_quotas:6100: Failed to enable quota tracking (type=0, err=-13, ino=3). Please run e2fsck to fix.
EXT4-fs (loop2): mount failed

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/13 17:16 android12-5.4 6b07fcd94a6a 44be8b44 .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-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/04/07 02:17 android12-5.4 41adfeb3d639 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/04/05 15:20 android12-5.4 41adfeb3d639 c53ea9c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/04/04 23:36 android12-5.4 41adfeb3d639 1c4febdb .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/04/04 18:20 android12-5.4 41adfeb3d639 1c4febdb .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/04/04 10:35 android12-5.4 41adfeb3d639 1c4febdb .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/04/03 13:56 android12-5.4 41adfeb3d639 996a9618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/28 14:59 android12-5.4 41adfeb3d639 9a1a9e31 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/28 07:15 android12-5.4 41adfeb3d639 6c09fb82 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/26 12:47 android12-5.4 41adfeb3d639 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/23 23:07 android12-5.4 41adfeb3d639 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/20 09:30 android12-5.4 41adfeb3d639 9209bc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/19 23:56 android12-5.4 41adfeb3d639 e20d7b13 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/17 20:28 android12-5.4 6b07fcd94a6a ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/12 05:18 android12-5.4 6b07fcd94a6a ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/12 03:54 android12-5.4 6b07fcd94a6a ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/07 10:03 android12-5.4 6b07fcd94a6a 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/05 23:50 android12-5.4 6b07fcd94a6a 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/02 04:01 android12-5.4 6b07fcd94a6a c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/02/27 17:57 android12-5.4 6b07fcd94a6a 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/02/22 04:18 android12-5.4 39762b7a60e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/02/06 16:25 android12-5.4 cb850525fc3e 577d049b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/02/06 00:59 android12-5.4 cb850525fc3e 4dc70884 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/02/05 22:28 android12-5.4 cb850525fc3e 4dc70884 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: use-after-free Read in __ext4_iget
2025/03/24 15:10 android12-5.4 41adfeb3d639 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-4-kasan KASAN: slab-out-of-bounds Read in __ext4_iget
* Struck through repros no longer work on HEAD.