[v6.1] KASAN: slab-out-of-bounds Read in reiserfs_xattr_get (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3594f306da12 Linux 6.1.147
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11a47c34580000
kernel config: https://syzkaller.appspot.com/x/.config?x=30b8ca4950f83e04
dashboard link: https://syzkaller.appspot.com/bug?extid=e7628770930b5ea2d3de
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5b0395e2ec6c/disk-3594f306.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c3ec331b7d5b/vmlinux-3594f306.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bff42068e062/bzImage-3594f306.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e76287...@syzkaller.appspotmail.com

... Log Wrap ... Log Wrap ... Log Wrap ...
==================================================================
BUG: KASAN: slab-out-of-bounds in reiserfs_xattr_get+0xfa/0x5a0 fs/reiserfs/xattr.c:674
Read of size 8 at addr ffff88802edd1598 by task syz.4.5456/16414

CPU: 1 PID: 16414 Comm: syz.4.5456 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
print_address_description mm/kasan/report.c:316 [inline]
print_report+0xa8/0x200 mm/kasan/report.c:418
kasan_report+0x10b/0x140 mm/kasan/report.c:522
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: 0033:0x7ff81ad8d550
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 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 9c 94 02 00 8b 44
RSP: 002b:00007ff81bb4edf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000010000 RCX: 00007ff81ad8d550
RDX: 0000000000010000 RSI: 0000200000000400 RDI: 00000000ffffff9c
RBP: 0000200000000400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000200000000400
R13: 00007ff81bb4eeb0 R14: 00000000000062ce R15: 00002000000001c0
</TASK>

Allocated by task 4274:
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]
fib_create_info+0xa53/0x2490 net/ipv4/fib_semantics.c:1459
fib_table_insert+0xc3/0x1b50 net/ipv4/fib_trie.c:1217
fib_magic+0x2c1/0x390 net/ipv4/fib_frontend.c:1118
fib_add_ifaddr+0x3f7/0x5e0 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:2039 [inline]
call_netdevice_notifiers net/core/dev.c:2053 [inline]
__dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1
dev_change_flags+0xe3/0x1a0 net/core/dev.c:8702
do_setlink+0xc31/0x3c40 net/core/rtnetlink.c:2833
__rtnl_newlink net/core/rtnetlink.c:3608 [inline]
rtnl_newlink+0x17d6/0x1ff0 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 ffff88802edd1400
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 152 bytes to the right of
256-byte region [ffff88802edd1400, ffff88802edd1500)

The buggy address belongs to the physical page:
page:ffffea0000bb7400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2edd0
head:ffffea0000bb7400 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4273, tgid 4273 (syz-executor), ts 83313385811, free_ts 83254462445
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:1794
allocate_slab mm/slub.c:1939 [inline]
new_slab+0x87/0x2c0 mm/slub.c:1992
___slab_alloc+0xbc6/0x1220 mm/slub.c:3180
__slab_alloc mm/slub.c:3279 [inline]
slab_alloc_node mm/slub.c:3364 [inline]
__kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3437
kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026
kmalloc include/linux/slab.h:563 [inline]
kzalloc include/linux/slab.h:699 [inline]
____ip_mc_inc_group+0x2ad/0xac0 net/ipv4/igmp.c:1452
__ip_mc_inc_group net/ipv4/igmp.c:1487 [inline]
ip_mc_inc_group net/ipv4/igmp.c:1493 [inline]
ip_mc_up+0x121/0x2f0 net/ipv4/igmp.c:1792
inetdev_event+0xe68/0x1410 net/ipv4/devinet.c:1591
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]
__dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1
dev_change_flags+0xe3/0x1a0 net/core/dev.c:8702
vlan_device_event+0x55a/0x1e00 net/8021q/vlan.c:493
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
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:3398 [inline]
__kmem_cache_alloc_node+0x140/0x260 mm/slub.c:3437
kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026
kmalloc include/linux/slab.h:563 [inline]
netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:643 [inline]
netdevice_event+0x325/0x900 drivers/infiniband/core/roce_gid_mgmt.c:802
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]
dev_set_mac_address+0x2c4/0x3d0 net/core/dev.c:8886
dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:8900
do_setlink+0x816/0x3c40 net/core/rtnetlink.c:2788
__rtnl_newlink net/core/rtnetlink.c:3608 [inline]
rtnl_newlink+0x17d6/0x1ff0 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

Memory state around the buggy address:
ffff88802edd1480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc
ffff88802edd1500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802edd1580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88802edd1600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88802edd1680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc
==================================================================


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