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KASAN: out-of-bounds Read in ext4_xattr_set_entry

Status: upstream: reported C repro on 2025/06/17 02:45
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+9e300b604d671b1676b3@syzkaller.appspotmail.com
First crash: 76d, last: 1d15h
▶ ▼ Bug presence (3)
Date Name Commit Repro Result
2025/08/31 linux-6.6.y (ToT) cc1a1c5b404a C [report] KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/12 upstream (ToT) 379f604cc3dc C [report] KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/31 upstream (ToT) c8bc81a52d5a C Didn't crash
▶ ▼ Similar bugs (18)
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 13d 60d 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 1449d 1908d 1/1 fixed on 2021/10/13 07:23
android-5-15 KASAN: out-of-bounds Read in ext4_xattr_set_entry 17 1 805d 805d 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 2974 4h10m 344d 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 859d 1624d 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 12d 170d 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 404 21h24m 836d 0/3 upstream: reported C repro on 2023/05/19 08:42
android-5-10 KASAN: out-of-bounds Read in ext4_xattr_set_entry 19 C inconclusive 13 10d 712d 0/2 upstream: reported C repro on 2023/09/20 02:40
linux-4.14 KASAN: out-of-bounds Read in ext4_xattr_set_entry 17 C error 2 1089d 1603d 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 230 3d13h 475d 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 913d 993d 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 817d 846d 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 852d 1052d 2/2 fixed on 2023/05/03 13:06
upstream KASAN: use-after-free Read in ext4_xattr_set_entry (5) ext4 19 2 1133d 1192d 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 847d 850d 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 1288d 1675d 20/29 fixed on 2022/03/28 10:17
android-5-10 general protection fault in ext4_xattr_set_entry 2 C error 2 1074d 1089d 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 814d 816d 2/2 fixed on 2023/06/13 02:27

Sample crash report:
==================================================================
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
Read of size 18446744073709551572 at addr ffff88806ceec850 by task syz.2.1275/10612

CPU: 1 PID: 10612 Comm: syz.2.1275 Not tainted 6.6.97-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x230 mm/kasan/report.c:475
 kasan_report+0x117/0x150 mm/kasan/report.c:588
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x288/0x290 mm/kasan/generic.c:187
 __asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
 ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
 ext4_xattr_block_set+0xae3/0x32a0 fs/ext4/xattr.c:2037
 ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
 ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
 __vfs_setxattr+0x431/0x470 fs/xattr.c:201
 __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
 vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
 do_setxattr fs/xattr.c:630 [inline]
 path_setxattr+0x362/0x550 fs/xattr.c:659
 __do_sys_lsetxattr fs/xattr.c:684 [inline]
 __se_sys_lsetxattr fs/xattr.c:680 [inline]
 __x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f08fab8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f08fba98038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f08fadb6080 RCX: 00007f08fab8e929
RDX: 0000200000000100 RSI: 00002000000000c0 RDI: 0000200000000080
RBP: 00007f08fac10b39 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f08fadb6080 R15: 00007ffed3df6608
 </TASK>

Allocated by task 10612:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
 kmemdup+0x2b/0x70 mm/util.c:131
 kmemdup include/linux/fortify-string.h:779 [inline]
 ext4_xattr_block_set+0x9e5/0x32a0 fs/ext4/xattr.c:1985
 ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
 ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
 __vfs_setxattr+0x431/0x470 fs/xattr.c:201
 __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
 vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
 do_setxattr fs/xattr.c:630 [inline]
 path_setxattr+0x362/0x550 fs/xattr.c:659
 __do_sys_lsetxattr fs/xattr.c:684 [inline]
 __se_sys_lsetxattr fs/xattr.c:680 [inline]
 __x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88806ceec800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 80 bytes inside of
 1024-byte region [ffff88806ceec800, ffff88806ceecc00)

The buggy address belongs to the physical page:
page:ffffea0001b3ba00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6cee8
head:ffffea0001b3ba00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841dc0 dead000000000100 dead000000000122
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 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 23, tgid 23 (kworker/1:0), ts 157841850531, free_ts 151074525762
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:650
 alloc_skb include/linux/skbuff.h:1284 [inline]
 nlmsg_new include/net/netlink.h:999 [inline]
 inet6_rt_notify+0xb4/0x240 net/ipv6/route.c:6228
 fib6_add_rt2node net/ipv6/ip6_fib.c:1255 [inline]
 fib6_add+0x1d9a/0x3d20 net/ipv6/ip6_fib.c:1484
 __ip6_ins_rt net/ipv6/route.c:1343 [inline]
 ip6_ins_rt+0xc9/0x120 net/ipv6/route.c:1353
 __ipv6_ifa_notify+0x62f/0xaa0 net/ipv6/addrconf.c:6252
 ipv6_ifa_notify net/ipv6/addrconf.c:6291 [inline]
 addrconf_dad_completed+0x181/0xd40 net/ipv6/addrconf.c:4290
 addrconf_dad_work+0xc4e/0x14e0 net/ipv6/addrconf.c:-1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 vfree+0x1a6/0x320 mm/vmalloc.c:2860
 kcov_put kernel/kcov.c:438 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:534
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x90b/0x23c0 kernel/exit.c:883
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88806ceec700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88806ceec780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88806ceec800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                 ^
 ffff88806ceec880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88806ceec900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (37):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/11 11:39 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/29 13:42 linux-6.6.y cc1a1c5b404a 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/28 23:11 linux-6.6.y cc1a1c5b404a d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/25 19:14 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/24 22:28 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/24 22:24 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/23 18:13 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/23 17:58 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/18 00:14 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/17 22:57 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/17 22:57 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/17 10:54 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/17 10:53 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/17 00:15 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/17 00:15 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/15 23:10 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/15 23:10 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/15 12:36 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/10 23:53 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/10 10:50 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/10 00:41 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/10 00:41 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/09 11:48 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/09 11:47 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/08 09:29 linux-6.6.y 3a8ababb8b6a 6a893178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/08 09:26 linux-6.6.y 3a8ababb8b6a 6a893178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/04 07:09 linux-6.6.y 3a8ababb8b6a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/01 12:46 linux-6.6.y 3a8ababb8b6a 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/08/01 10:50 linux-6.6.y 3a8ababb8b6a 0c075d67 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/21 16:52 linux-6.6.y d96eb99e2f0e 56d87229 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/19 05:05 linux-6.6.y d96eb99e2f0e 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/19 04:59 linux-6.6.y d96eb99e2f0e 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/18 14:19 linux-6.6.y d96eb99e2f0e 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/18 13:41 linux-6.6.y d96eb99e2f0e 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/13 02:13 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/07/10 18:24 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
2025/06/17 02:44 linux-6.6.y c2603c511feb cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: out-of-bounds Read in ext4_xattr_set_entry
* Struck through repros no longer work on HEAD.