syzbot


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: 65d, last: 1d05h
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get 17 1 302d 302d 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 1 23d 23d 0/2 upstream: reported on 2025/09/25 10:35
linux-5.15 KASAN: slab-out-of-bounds Read in reiserfs_xattr_get 17 3 186d 259d 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 629d 625d 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 763d 1649d 0/29 auto-obsoleted due to no activity on 2023/12/25 15:39

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 ffff88807c1bb598 by task syz.4.7861/22423

CPU: 1 PID: 22423 Comm: syz.4.7861 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e 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/0x680 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+0x3bf/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:3254
 do_open fs/namei.c:3624 [inline]
 path_openat+0x245f/0x2e70 fs/namei.c:3783
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810
 do_sys_openat2+0x142/0x490 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f510498d810
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 69 95 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 bc 95 02 00 8b 44
RSP: 002b:00007f5105786df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000010000 RCX: 00007f510498d810
RDX: 0000000000010000 RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 0000200000000040 R08: 0000000000000000 R09: 0000000000800c08
R10: 0000000000000000 R11: 0000000000000293 R12: 0000200000000040
R13: 00007f5105786eb0 R14: 000000000000624a R15: 00002000000007c0
 </TASK>

Allocated by task 4521:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:936 [inline]
 __kmalloc+0xb0/0x240 mm/slab_common.c:949
 kmalloc include/linux/slab.h:568 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 new_dir fs/proc/proc_sysctl.c:973 [inline]
 get_subdir fs/proc/proc_sysctl.c:1017 [inline]
 __register_sysctl_table+0x96c/0xe70 fs/proc/proc_sysctl.c:1379
 neigh_sysctl_register+0x993/0xa70 net/core/neighbour.c:3858
 devinet_sysctl_register+0xa8/0x1f0 net/ipv4/devinet.c:2649
 inetdev_init+0x2b4/0x4f0 net/ipv4/devinet.c:280
 inetdev_event+0x270/0x1410 net/ipv4/devinet.c:1547
 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:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 register_netdevice+0x1600/0x1aa0 net/core/dev.c:10237
 macsec_newlink+0x65a/0x1030 drivers/net/macsec.c:4115
 rtnl_newlink_create net/core/rtnetlink.c:3422 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3642 [inline]
 rtnl_newlink+0x14c4/0x1ff0 net/core/rtnetlink.c:3655
 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6153
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x44f/0x5c0 net/socket.c:2153
 __do_sys_sendto net/socket.c:2165 [inline]
 __se_sys_sendto net/socket.c:2161 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2161
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88807c1bb400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 152 bytes to the right of
 256-byte region [ffff88807c1bb400, ffff88807c1bb500)

The buggy address belongs to the physical page:
page:ffffea0001f06e80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c1ba
head:ffffea0001f06e80 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888017441b40
raw: 0000000000000000 0000000000100010 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 4519, tgid 4519 (syz-executor), ts 84851616789, free_ts 84832988397
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 alloc_slab_page+0x5d/0x160 mm/slub.c:1799
 allocate_slab mm/slub.c:1944 [inline]
 new_slab+0x87/0x2c0 mm/slub.c:1997
 ___slab_alloc+0xbc6/0x1230 mm/slub.c:3154
 __slab_alloc mm/slub.c:3240 [inline]
 slab_alloc_node mm/slub.c:3325 [inline]
 __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398
 __do_kmalloc_node mm/slab_common.c:935 [inline]
 __kmalloc+0xa0/0x240 mm/slab_common.c:949
 kmalloc include/linux/slab.h:568 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 new_dir fs/proc/proc_sysctl.c:973 [inline]
 get_subdir fs/proc/proc_sysctl.c:1017 [inline]
 __register_sysctl_table+0x96c/0xe70 fs/proc/proc_sysctl.c:1379
 neigh_sysctl_register+0x993/0xa70 net/core/neighbour.c:3858
 devinet_sysctl_register+0xa8/0x1f0 net/ipv4/devinet.c:2649
 inetdev_init+0x2b4/0x4f0 net/ipv4/devinet.c:280
 inetdev_event+0x270/0x1410 net/ipv4/devinet.c:1547
 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:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 register_netdevice+0x1600/0x1aa0 net/core/dev.c:10237
 geneve_configure+0x637/0xa70 drivers/net/geneve.c:1449
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479
 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:305
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 __kmem_cache_alloc_node+0x140/0x260 mm/slub.c:3398
 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 kset_create lib/kobject.c:950 [inline]
 kset_create_and_add+0x56/0x160 lib/kobject.c:993
 register_queue_kobjects net/core/net-sysfs.c:1764 [inline]
 netdev_register_kobject+0x1a0/0x310 net/core/net-sysfs.c:2017
 register_netdevice+0x12b9/0x1aa0 net/core/dev.c:10204
 macsec_newlink+0x65a/0x1030 drivers/net/macsec.c:4115
 rtnl_newlink_create net/core/rtnetlink.c:3422 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3642 [inline]
 rtnl_newlink+0x14c4/0x1ff0 net/core/rtnetlink.c:3655
 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6153
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344

Memory state around the buggy address:
 ffff88807c1bb480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807c1bb500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807c1bb580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff88807c1bb600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807c1bb680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.