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

Status: upstream: reported on 2026/04/14 22:58
Reported-by: syzbot+4f7007a58fe4293f83f8@syzkaller.appspotmail.com
First crash: 102d, last: 60d
▶ ▼ 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 74d 74d 0/3 upstream: reported on 2026/05/13 09:19
linux-6.1 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get (2) 17 6 34d 345d 0/3 upstream: reported on 2025/08/15 02:35
linux-6.1 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get 17 1 583d 583d 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 277d 304d 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 466d 540d 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 909d 905d 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 1044d 1930d 0/29 auto-obsoleted due to no activity on 2023/12/25 15:39

Sample crash report:
loop0: detected capacity change from 0 to 32768
 ... Log Wrap ... Log Wrap ... Log Wrap ...
==================================================================
BUG: KASAN: slab-out-of-bounds in reiserfs_xattr_get+0xfe/0x5a0 fs/reiserfs/xattr.c:676
Read of size 8 at addr ffff88802671f598 by task syz.0.11350/30953

CPU: 0 PID: 30953 Comm: syz.0.11350 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 reiserfs_xattr_get+0xfe/0x5a0 fs/reiserfs/xattr.c:676
 reiserfs_get_acl+0x7e/0x6a0 fs/reiserfs/xattr_acl.c:215
 __get_acl+0x273/0x400 fs/posix_acl.c:160
 check_acl+0x3a/0x150 fs/namei.c:310
 acl_permission_check fs/namei.c:355 [inline]
 generic_permission+0x381/0x590 fs/namei.c:408
 do_inode_permission fs/namei.c:462 [inline]
 inode_permission+0x23d/0x480 fs/namei.c:529
 may_open+0x2e9/0x440 fs/namei.c:3268
 do_open fs/namei.c:3638 [inline]
 path_openat+0x268c/0x3230 fs/namei.c:3797
 do_filp_open+0x1f5/0x430 fs/namei.c:3824
 do_sys_openat2+0x134/0x1d0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f86eb35d68e
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:00007f86ec295da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f86ec2966c0 RCX: 00007f86eb35d68e
RDX: 0000000000010000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 0000200000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f86ec295ea0 R14: 0000000000006246 R15: 0000200000000140
 </TASK>

Allocated by task 28176:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc+0xb4/0x230 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 new_dir fs/proc/proc_sysctl.c:969 [inline]
 get_subdir fs/proc/proc_sysctl.c:1013 [inline]
 sysctl_mkdir_p fs/proc/proc_sysctl.c:1308 [inline]
 __register_sysctl_table+0xac9/0x1240 fs/proc/proc_sysctl.c:1389
 __devinet_sysctl_register+0x375/0x470 net/ipv4/devinet.c:2633
 devinet_sysctl_register+0x17c/0x1f0 net/ipv4/devinet.c:2673
 inetdev_init+0x2b4/0x4f0 net/ipv4/devinet.c:287
 inetdev_event+0x324/0x1630 net/ipv4/devinet.c:1568
 notifier_call_chain+0x197/0x380 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
 call_netdevice_notifiers net/core/dev.c:2091 [inline]
 register_netdevice+0x16a5/0x1bb0 net/core/dev.c:10351
 bond_newlink+0x3d/0x90 drivers/net/bonding/bond_netlink.c:605
 rtnl_newlink_create net/core/rtnetlink.c:3521 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3741 [inline]
 rtnl_newlink+0x1542/0x20a0 net/core/rtnetlink.c:3754
 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6476
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 __call_rcu_common kernel/rcu/tree.c:2721 [inline]
 call_rcu+0x153/0x950 kernel/rcu/tree.c:2837
 team_vlan_rx_kill_vid+0x87/0xd0 drivers/net/team/team.c:1935
 vlan_kill_rx_filter_info net/8021q/vlan_core.c:222 [inline]
 __vlan_vid_del net/8021q/vlan_core.c:362 [inline]
 vlan_vid_del+0x469/0x750 net/8021q/vlan_core.c:387
 vlan_vid0_del net/8021q/vlan.c:389 [inline]
 vlan_device_event+0x3d8/0x1f10 net/8021q/vlan.c:416
 notifier_call_chain+0x197/0x380 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
 call_netdevice_notifiers net/core/dev.c:2091 [inline]
 __dev_notify_flags+0x16e/0x310 net/core/dev.c:8764
 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8800
 do_setlink+0xc58/0x4130 net/core/rtnetlink.c:2909
 __rtnl_newlink net/core/rtnetlink.c:3707 [inline]
 rtnl_newlink+0x17da/0x20a0 net/core/rtnetlink.c:3754
 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6476
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88802671f400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 154 bytes to the right of
 allocated 254-byte region [ffff88802671f400, ffff88802671f4fe)

The buggy address belongs to the physical page:
page:ffffea000099c780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2671e
head:ffffea000099c780 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c41b40 ffffea0001df6880 dead000000000005
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6379, tgid 6379 (syz-executor), ts 82552674484, free_ts 76165604114
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581
 prep_new_page mm/page_alloc.c:1588 [inline]
 get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500
 alloc_slab_page+0x5d/0x160 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2081
 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0xa4/0x230 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 fib_create_info+0xa61/0x2460 net/ipv4/fib_semantics.c:1459
 fib_table_insert+0xc6/0x1b20 net/ipv4/fib_trie.c:1217
 fib_magic+0x2e5/0x3c0 net/ipv4/fib_frontend.c:1118
 fib_add_ifaddr+0x144/0x5e0 net/ipv4/fib_frontend.c:1140
 fib_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500
 notifier_call_chain+0x197/0x380 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
 call_netdevice_notifiers net/core/dev.c:2091 [inline]
 __dev_notify_flags+0x1aa/0x310 net/core/dev.c:8762
 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8800
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1181 [inline]
 free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
 vfree+0x1a6/0x320 mm/vmalloc.c:2868
 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+0x1d4/0x260 kernel/task_work.c:245
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x95a/0x2460 kernel/exit.c:884
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1026
 get_signal+0x12fc/0x13f0 kernel/signal.c:2902
 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 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:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88802671f480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06
 ffff88802671f500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802671f580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff88802671f600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802671f680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/27 11:31 linux-6.6.y 0a40c6fbd105 8777bdc3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
2026/04/14 22:57 linux-6.6.y 8cee53b8eaeb e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
* Struck through repros no longer work on HEAD.