syzbot


KASAN: out-of-bounds Read in ext4_xattr_set_entry

Status: upstream: reported C repro on 2023/09/20 02:40
Reported-by: syzbot+9b8029e222e845c4480b@syzkaller.appspotmail.com
First crash: 701d, last: 1h01m
Fix bisection: the issue occurs on the latest tested release (bisect log)
  
Similar bugs (28)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: out-of-bounds Read in ext4_xattr_set_entry (2) origin:lts 17 C 3 3d06h 50d 0/2 upstream: reported C repro on 2025/07/03 01:48
linux-4.19 KASAN: use-after-free Read in ext4_xattr_set_entry (2) 19 C done 7 1439d 1897d 1/1 fixed on 2021/10/13 07:23
android-5-15 KASAN: out-of-bounds Read in ext4_xattr_set_entry 17 1 794d 794d 0/2 auto-obsoleted due to no activity on 2023/09/17 07:02
upstream KASAN: out-of-bounds Read in ext4_xattr_set_entry ext4 24 C error 2850 4h04m 334d 0/29 upstream: reported C repro on 2024/09/22 00:16
android-54 KASAN: out-of-bounds Read in ext4_xattr_set_entry ext4 17 C 14 848d 1614d 0/2 auto-obsoleted due to no activity on 2023/08/23 09:06
linux-5.15 KASAN: out-of-bounds Read in ext4_xattr_set_entry origin:upstream 17 C error 24 2d04h 159d 0/3 upstream: reported C repro on 2025/03/15 11:50
linux-6.1 KASAN: out-of-bounds Read in ext4_xattr_set_entry missing-backport origin:lts-only 17 C inconclusive 401 2d14h 825d 0/3 upstream: reported C repro on 2023/05/19 08:42
linux-6.6 KASAN: out-of-bounds Read in ext4_xattr_set_entry origin:upstream 17 C 30 4d01h 65d 0/2 upstream: reported C repro on 2025/06/17 02:45
linux-4.14 KASAN: out-of-bounds Read in ext4_xattr_set_entry 17 C error 2 1078d 1592d 0/1 upstream: reported C repro on 2021/04/12 14:20
android-6-1 KASAN: out-of-bounds Read in ext4_xattr_set_entry origin:lts 17 C 226 11d 465d 0/2 upstream: reported C repro on 2024/05/13 18:18
android-5-15 general protection fault in ext4_xattr_set_entry 2 C error 1 903d 983d 2/2 fixed on 2023/03/28 12:29
android-5-10 general protection fault in ext4_xattr_set_entry (4) 2 C error 62 806d 835d 2/2 fixed on 2023/06/07 17:22
android-5-10 general protection fault in ext4_xattr_set_entry (2) ext4 2 C error 423 841d 1041d 2/2 fixed on 2023/05/03 13:06
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (5) ext4 19 2 1123d 1181d 0/29 auto-obsoleted due to no activity on 2022/11/22 17:19
android-5-10 general protection fault in ext4_xattr_set_entry (3) 2 C error 9 837d 840d 2/2 fixed on 2023/05/08 19:06
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (4) ext4 24 C error done 21 1277d 1664d 20/29 fixed on 2022/03/28 10:17
android-5-10 general protection fault in ext4_xattr_set_entry 2 C error 2 1064d 1078d 0/2 closed as invalid on 2022/09/26 18:30
android-5-10 general protection fault in ext4_xattr_set_entry (5) 2 C done 11 803d 805d 2/2 fixed on 2023/06/13 02:27
linux-4.14 KASAN: use-after-free Read in ext4_xattr_set_entry (3) 19 C error 1 1273d 1758d 0/1 upstream: reported C repro on 2020/10/28 15:08
android-414 KASAN: use-after-free Read in ext4_xattr_set_entry (2) 19 6 2121d 2177d 0/1 auto-closed as invalid on 2020/02/28 13:35
linux-4.14 KASAN: use-after-free Read in ext4_xattr_set_entry (2) 19 1 1977d 1977d 0/1 auto-closed as invalid on 2020/07/21 03:20
upstream KASAN: use-after-free Read in ext4_xattr_set_entry ext4 19 1 2582d 2582d 0/29 closed as invalid on 2018/07/29 11:55
android-414 KASAN: use-after-free Read in ext4_xattr_set_entry 19 4 2429d 2322d 0/1 auto-closed as invalid on 2019/06/26 01:15
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (3) ext4 19 4 1873d 1991d 0/29 auto-closed as invalid on 2020/11/02 08:32
linux-4.19 KASAN: use-after-free Read in ext4_xattr_set_entry 19 syz done 10 2001d 2249d 1/1 fixed on 2020/03/30 09:03
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (2) ext4 19 C done 19 2075d 2484d 15/29 fixed on 2020/02/14 01:19
android-54 KASAN: use-after-free Read in ext4_xattr_set_entry 19 6 1841d 2022d 0/2 auto-closed as invalid on 2020/12/04 21:44
linux-4.14 KASAN: use-after-free Read in ext4_xattr_set_entry 19 C done 9 2029d 2121d 1/1 fixed on 2020/03/01 21:06
Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/07/29 07:50 10m retest repro android13-5.10-lts report log
2025/07/13 00:14 12m retest repro android13-5.10-lts report log
2025/06/28 16:47 6m retest repro android13-5.10-lts report log
2025/06/28 16:47 7m retest repro android13-5.10-lts report log
2025/06/28 16:47 6m retest repro android13-5.10-lts report log
2025/05/19 17:29 44m retest repro android13-5.10-lts report log
2025/04/27 05:28 13m retest repro android13-5.10-lts report log
2025/04/06 02:51 10m retest repro android13-5.10-lts report log
2025/03/09 02:38 1h05m retest repro android13-5.10-lts report log
2024/12/29 01:36 13m retest repro android13-5.10-lts OK log
Fix bisection attempts (7)
Created Duration User Patch Repo Result
2024/05/20 17:04 45m bisect fix android13-5.10-lts OK (0) job log
2024/04/16 22:07 1h18m bisect fix android13-5.10-lts OK (0) job log log
2024/03/14 11:41 1h47m bisect fix android13-5.10-lts OK (0) job log log
2024/02/11 02:19 1h09m bisect fix android13-5.10-lts OK (0) job log log
2024/01/05 01:17 1h12m bisect fix android13-5.10-lts OK (0) job log log
2023/12/05 19:48 1h18m bisect fix android13-5.10-lts OK (0) job log log
2023/11/04 13:28 1h06m bisect fix android13-5.10-lts OK (0) job log log

Sample crash report:
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x1339/0x36c0 fs/ext4/xattr.c:1740
Read of size 18446744073709551540 at addr ffff888104bef070 by task syz-executor340/282

CPU: 0 PID: 282 Comm: syz-executor340 Not tainted 5.10.240-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
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
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x280/0x290 mm/kasan/generic.c:189
 memmove+0x2d/0x70 mm/kasan/shadow.c:54
 ext4_xattr_set_entry+0x1339/0x36c0 fs/ext4/xattr.c:1740
 ext4_xattr_block_set+0x92f/0x2a50 fs/ext4/xattr.c:1997
 ext4_xattr_set_handle+0xba5/0x12a0 fs/ext4/xattr.c:2403
 ext4_xattr_set+0x1ec/0x320 fs/ext4/xattr.c:2513
 ext4_xattr_trusted_set+0x3b/0x50 fs/ext4/xattr_trusted.c:37
 __vfs_setxattr+0x42a/0x480 fs/xattr.c:177
 __vfs_setxattr_noperm+0x11e/0x4e0 fs/xattr.c:208
 __vfs_setxattr_locked+0x203/0x220 fs/xattr.c:266
 vfs_setxattr+0x8d/0x1c0 fs/xattr.c:283
 setxattr+0x1a9/0x370 fs/xattr.c:548
 path_setxattr+0x110/0x210 fs/xattr.c:567
 __do_sys_lsetxattr fs/xattr.c:589 [inline]
 __se_sys_lsetxattr fs/xattr.c:585 [inline]
 __x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:585
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f4d0fca6af9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc105e3b38 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00002000000001c0 RCX: 00007f4d0fca6af9
RDX: 0000200000000040 RSI: 0000200000000300 RDI: 0000200000000100
RBP: 0000200000000040 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fe37 R11: 0000000000000246 R12: 0072657070752e79
R13: 0032656c69662f2e R14: 0031656c69662f2e R15: 0000000000000001

Allocated by task 0:
(stack is not available)

The buggy address belongs to the object at ffff888104bef000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 112 bytes inside of
 1024-byte region [ffff888104bef000, ffff888104bef400)
The buggy address belongs to the page:
page:ffffea000412fa00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104be8
head:ffffea000412fa00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042f00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 282, ts 29737134338, free_ts 29656987537
 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]
 __kmalloc+0x201/0x330 mm/slub.c:4029
 __kmalloc_node include/linux/slab.h:418 [inline]
 kmalloc_node include/linux/slab.h:575 [inline]
 kvmalloc_node+0x88/0x130 mm/util.c:612
 kvmalloc include/linux/mm.h:822 [inline]
 setxattr+0x1c0/0x370 fs/xattr.c:530
 path_setxattr+0x110/0x210 fs/xattr.c:567
 __do_sys_lsetxattr fs/xattr.c:589 [inline]
 __se_sys_lsetxattr fs/xattr.c:585 [inline]
 __x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:585
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 __free_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629
 free_the_page mm/page_alloc.c:5418 [inline]
 __free_pages+0xdd/0x380 mm/page_alloc.c:5427
 __free_slab+0xcf/0x190 mm/slub.c:1894
 free_slab mm/slub.c:1909 [inline]
 discard_slab mm/slub.c:1915 [inline]
 unfreeze_partials+0x15f/0x190 mm/slub.c:2410
 put_cpu_partial+0xc1/0x180 mm/slub.c:2446
 __slab_free+0x2c9/0x3a0 mm/slub.c:3095
 do_slab_free mm/slub.c:3191 [inline]
 ___cache_free+0x111/0x130 mm/slub.c:3210
 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440
 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
 getname_flags+0xb9/0x500 fs/namei.c:141
 user_path_at_empty+0x2f/0x50 fs/namei.c:2740
 user_path_at include/linux/namei.h:60 [inline]
 vfs_statx+0xff/0x520 fs/stat.c:193

Memory state around the buggy address:
 ffff888104beef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888104beef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888104bef000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/22 01:13 android13-5.10-lts 1154f779f3f3 3e79b825 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/05/31 07:57 android13-5.10-lts cf6ed0f1511d 3d2f584d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/04/13 00:43 android13-5.10-lts e0b88ee5f09c 0bd6db41 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/03/22 17:36 android13-5.10-lts 094fc3778d6b c6512ef7 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2023/09/20 02:39 android13-5.10-lts a27512601c2d 0b6a67ac .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] [mounted in repro #3] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/05/27 01:52 android13-5.10-lts 7e2543346ff7 874a1386 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_xattr_set_entry
2025/06/14 14:22 android13-5.10-lts d76d4cd0623a 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/06/10 15:53 android13-5.10-lts d76d4cd0623a 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/01/07 18:37 android13-5.10-lts 49e8ba0a684f f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2024/12/30 23:50 android13-5.10-lts 49e8ba0a684f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2024/12/10 23:09 android13-5.10-lts 0eb852f47fe5 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2024/11/22 13:20 android13-5.10-lts b14940b90491 4b25d554 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
2024/10/02 20:37 android13-5.10-lts e5e5644ea27f 02f9582a .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry
* Struck through repros no longer work on HEAD.