KASAN: slab-out-of-bounds Read in reiserfs_xattr_get (2)

Status: upstream: reported on 2025/08/15 02:35
Reported-by: syzbot+e7628770930b5ea2d3de@syzkaller.appspotmail.com
First crash: 343d, last: 32d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get (2) 17 1 72d 72d 0/3 upstream: reported on 2026/05/13 09:19
linux-6.1 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get 17 1 581d 581d 0/3 auto-obsoleted due to no activity on 2025/03/30 06:16
linux-6.6 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get 17 2 275d 302d 0/2 auto-obsoleted due to no activity on 2026/01/30 03:22
linux-5.15 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get 17 3 465d 538d 0/3 auto-obsoleted due to no activity on 2025/07/24 22:48
upstream KASAN: slab-out-of-bounds Read in reiserfs_xattr_get (2) fs 17 1 908d 904d 0/29 auto-obsoleted due to no activity on 2024/05/07 19:35
upstream KASAN: slab-out-of-bounds Read in reiserfs_xattr_get fs 19 106 1042d 1928d 0/29 auto-obsoleted due to no activity on 2023/12/25 15:39
linux-6.6 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get (2) 17 2 58d 101d 0/2 upstream: reported on 2026/04/14 22:58

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in reiserfs_xattr_get+0xfa/0x5a0 fs/reiserfs/xattr.c:674
Read of size 8 at addr ffff8880287ca598 by task syz.0.7419/20583

CPU: 0 PID: 20583 Comm: syz.0.7419 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 reiserfs_xattr_get+0xfa/0x5a0 fs/reiserfs/xattr.c:674
 reiserfs_get_acl+0x7a/0x6e0 fs/reiserfs/xattr_acl.c:214
 get_acl+0x154/0x250 fs/posix_acl.c:153
 check_acl+0x3a/0x150 fs/namei.c:309
 acl_permission_check fs/namei.c:354 [inline]
 generic_permission+0x3a5/0x510 fs/namei.c:407
 do_inode_permission fs/namei.c:461 [inline]
 inode_permission+0x239/0x480 fs/namei.c:528
 may_open+0x262/0x400 fs/namei.c:3262
 do_open fs/namei.c:3632 [inline]
 path_openat+0x251a/0x2f10 fs/namei.c:3791
 do_filp_open+0x1ee/0x420 fs/namei.c:3818
 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcbf115d68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fcbf1f82da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fcbf1f836c0 RCX: 00007fcbf115d68e
RDX: 0000000000010000 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 0000200000000040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000100
R13: 00007fcbf1f82ea0 R14: 0000000000000318 R15: 0000200000000240
 </TASK>

Allocated by task 20583:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 hfs_fill_super+0x139/0x14e0 fs/hfs/super.c:386
 mount_bdev+0x28a/0x3c0 fs/super.c:1443
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x247/0xa40 fs/namespace.c:3078
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486
 kvfree_call_rcu+0x103/0x890 kernel/rcu/tree.c:3405
 neigh_periodic_work+0x3f2/0xd70 net/core/neighbour.c:1010
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Second to last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486
 call_rcu+0x14f/0x950 kernel/rcu/tree.c:2849
 netdev_for_each_tx_queue include/linux/netdevice.h:2465 [inline]
 dev_shutdown+0x91/0x440 net/sched/sch_generic.c:1465
 unregister_netdevice_many_notify+0xa7e/0x1990 net/core/dev.c:11014
 unregister_netdevice_many net/core/dev.c:11077 [inline]
 default_device_exit_batch+0x95e/0x9f0 net/core/dev.c:11549
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x78e/0xba0 net/core/net_namespace.c:640
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff8880287ca000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 408 bytes to the right of
 1024-byte region [ffff8880287ca000, ffff8880287ca400)

The buggy address belongs to the physical page:
page:ffffea0000a1f200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x287c8
head:ffffea0000a1f200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888017441dc0
raw: 0000000000000000 0000000000100010 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4708, tgid 4708 (syz-executor), ts 69900612366, free_ts 69302525024
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560
 prep_new_page mm/page_alloc.c:2567 [inline]
 get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358
 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658
 alloc_slab_page+0x5d/0x180 mm/slub.c:1799
 allocate_slab mm/slub.c:1944 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:1997
 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154
 __slab_alloc mm/slub.c:3240 [inline]
 slab_alloc_node mm/slub.c:3325 [inline]
 __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398
 __do_kmalloc_node mm/slab_common.c:935 [inline]
 __kmalloc_node_track_caller+0xa0/0x240 mm/slab_common.c:956
 kmalloc_reserve net/core/skbuff.c:446 [inline]
 __alloc_skb+0x226/0x7d0 net/core/skbuff.c:515
 alloc_skb include/linux/skbuff.h:1303 [inline]
 nlmsg_new include/net/netlink.h:998 [inline]
 rtmsg_fib+0xd7/0x440 net/ipv4/fib_semantics.c:522
 fib_table_insert+0xd4e/0x1af0 net/ipv4/fib_trie.c:1385
 fib_magic+0x2ca/0x3b0 net/ipv4/fib_frontend.c:1118
 fib_add_ifaddr+0x3e2/0x5c0 net/ipv4/fib_frontend.c:1162
 fib_netdev_event+0x361/0x470 net/ipv4/fib_frontend.c:1500
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline]
 call_netdevice_notifiers net/core/dev.c:2066 [inline]
 __dev_notify_flags+0x1a7/0x310 net/core/dev.c:8715
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1487 [inline]
 free_pcp_prepare mm/page_alloc.c:1537 [inline]
 free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509
 free_slab mm/slub.c:2036 [inline]
 discard_slab mm/slub.c:2042 [inline]
 __unfreeze_partials+0x188/0x1e0 mm/slub.c:2591
 put_cpu_partial+0x17c/0x250 mm/slub.c:2667
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc_lru+0x182/0x2e0 mm/slub.c:3390
 __d_alloc+0x2e/0x6e0 fs/dcache.c:1774
 d_alloc_anon fs/dcache.c:1875 [inline]
 d_alloc_cursor+0x40/0xd0 fs/dcache.c:1881
 dcache_dir_open+0x37/0x70 fs/libfs.c:83
 do_dentry_open+0x7dd/0x10b0 fs/open.c:882
 do_open fs/namei.c:3634 [inline]
 path_openat+0x2674/0x2f10 fs/namei.c:3791
 do_filp_open+0x1ee/0x420 fs/namei.c:3818
 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320

Memory state around the buggy address:
 ffff8880287ca480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880287ca500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880287ca580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff8880287ca600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880287ca680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/22 16:58 linux-6.1.y fdb6fcb41cc7 5a630be6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
2026/03/25 08:36 linux-6.1.y f2ddafa93a25 8ee77f7d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
2026/01/21 16:46 linux-6.1.y cd9b81672742 8fc37797 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
2025/10/17 21:57 linux-6.1.y c2fda4b3f577 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
2025/09/26 18:56 linux-6.1.y 7b34dc04e4ff 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
2025/08/15 02:35 linux-6.1.y 3594f306da12 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
* Struck through repros no longer work on HEAD.