[v6.6] KASAN: slab-out-of-bounds Read in hfsplus_uni2asc
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syzbot
Jul 22, 2025, 6:35:38 AM7/22/25
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: d96eb99e2f0e Linux 6.6.99
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16945f22580000
kernel config: https://syzkaller.appspot.com/x/.config?x=bfd82343ac39d3b
dashboard link: https://syzkaller.appspot.com/bug?extid=310389f7e95350930d25
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/11b332f11d00/disk-d96eb99e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8a063193b98f/vmlinux-d96eb99e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b36214b822e5/bzImage-d96eb99e.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+310389...@syzkaller.appspotmail.com
loop5: detected capacity change from 0 to 1024
==================================================================
BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
Read of size 2 at addr ffff888030125218 by task syz.5.1011/10241
CPU: 0 PID: 10241 Comm: syz.5.1011 Not tainted 6.6.99-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/0x200 mm/kasan/report.c:466
kasan_report+0x117/0x150 mm/kasan/report.c:579
hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
hfsplus_listxattr+0x58f/0xb80 fs/hfsplus/xattr.c:736
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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: 0033:0x7fd244d8e9a9
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:00007fd245bd7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3
RAX: ffffffffffffffda RBX: 00007fd244fb5fa0 RCX: 00007fd244d8e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007fd244e10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd244fb5fa0 R15: 00007ffea8b4a578
</TASK>
Allocated by task 10241:
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+0xb4/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
hfsplus_find_init+0x89/0x1d0 fs/hfsplus/bfind.c:21
hfsplus_listxattr+0x390/0xb80 fs/hfsplus/xattr.c:695
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
__call_rcu_common kernel/rcu/tree.c:2721 [inline]
call_rcu+0x158/0x930 kernel/rcu/tree.c:2837
qdisc_put net/sched/sch_generic.c:1104 [inline]
dev_shutdown+0x34f/0x440 net/sched/sch_generic.c:1492
unregister_netdevice_many_notify+0x8d2/0x1810 net/core/dev.c:11064
ip_tunnel_delete_nets+0x31c/0x360 net/ipv4/ip_tunnel.c:1171
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x77f/0xb90 net/core/net_namespace.c:652
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
The buggy address belongs to the object at ffff888030125000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes to the right of
allocated 536-byte region [ffff888030125000, ffff888030125218)
The buggy address belongs to the physical page:
page:ffffea0000c04800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888030127800 pfn:0x30120
head:ffffea0000c04800 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 ffffea0001e04800 dead000000000002
raw: ffff888030127800 000000008010000f 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5788, tgid 5788 (syz-executor), ts 80213444160, free_ts 80177290147
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_route_add+0x8a/0x130 net/ipv6/route.c:3893
addrconf_prefix_route net/ipv6/addrconf.c:2451 [inline]
fixup_permanent_addr net/ipv6/addrconf.c:3571 [inline]
addrconf_permanent_addr+0x659/0x980 net/ipv6/addrconf.c:3595
addrconf_notify+0x996/0x1010 net/ipv6/addrconf.c:3667
notifier_call_chain+0x197/0x390 kernel/notifier.c:93
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
discard_slab mm/slub.c:2122 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
put_cpu_partial+0x17c/0x250 mm/slub.c:2738
__slab_free+0x31d/0x410 mm/slub.c:3686
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3530
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
alloc_skb include/linux/skbuff.h:1284 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1194 [inline]
netlink_sendmsg+0x65b/0xbe0 net/netlink/af_netlink.c:1879
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x46a/0x620 net/socket.c:2201
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xde/0xf0 net/socket.c:2209
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
Memory state around the buggy address:
ffff888030125100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888030125180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888030125200: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888030125280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888030125300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: d96eb99e2f0e Linux 6.6.99
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16945f22580000
kernel config: https://syzkaller.appspot.com/x/.config?x=bfd82343ac39d3b
dashboard link: https://syzkaller.appspot.com/bug?extid=310389f7e95350930d25
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/11b332f11d00/disk-d96eb99e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8a063193b98f/vmlinux-d96eb99e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b36214b822e5/bzImage-d96eb99e.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+310389...@syzkaller.appspotmail.com
loop5: detected capacity change from 0 to 1024
==================================================================
BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
Read of size 2 at addr ffff888030125218 by task syz.5.1011/10241
CPU: 0 PID: 10241 Comm: syz.5.1011 Not tainted 6.6.99-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/0x200 mm/kasan/report.c:466
kasan_report+0x117/0x150 mm/kasan/report.c:579
hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
hfsplus_listxattr+0x58f/0xb80 fs/hfsplus/xattr.c:736
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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: 0033:0x7fd244d8e9a9
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:00007fd245bd7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3
RAX: ffffffffffffffda RBX: 00007fd244fb5fa0 RCX: 00007fd244d8e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007fd244e10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd244fb5fa0 R15: 00007ffea8b4a578
</TASK>
Allocated by task 10241:
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+0xb4/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
hfsplus_find_init+0x89/0x1d0 fs/hfsplus/bfind.c:21
hfsplus_listxattr+0x390/0xb80 fs/hfsplus/xattr.c:695
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
__call_rcu_common kernel/rcu/tree.c:2721 [inline]
call_rcu+0x158/0x930 kernel/rcu/tree.c:2837
qdisc_put net/sched/sch_generic.c:1104 [inline]
dev_shutdown+0x34f/0x440 net/sched/sch_generic.c:1492
unregister_netdevice_many_notify+0x8d2/0x1810 net/core/dev.c:11064
ip_tunnel_delete_nets+0x31c/0x360 net/ipv4/ip_tunnel.c:1171
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x77f/0xb90 net/core/net_namespace.c:652
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
The buggy address belongs to the object at ffff888030125000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes to the right of
allocated 536-byte region [ffff888030125000, ffff888030125218)
The buggy address belongs to the physical page:
page:ffffea0000c04800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888030127800 pfn:0x30120
head:ffffea0000c04800 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 ffffea0001e04800 dead000000000002
raw: ffff888030127800 000000008010000f 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5788, tgid 5788 (syz-executor), ts 80213444160, free_ts 80177290147
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_route_add+0x8a/0x130 net/ipv6/route.c:3893
addrconf_prefix_route net/ipv6/addrconf.c:2451 [inline]
fixup_permanent_addr net/ipv6/addrconf.c:3571 [inline]
addrconf_permanent_addr+0x659/0x980 net/ipv6/addrconf.c:3595
addrconf_notify+0x996/0x1010 net/ipv6/addrconf.c:3667
notifier_call_chain+0x197/0x390 kernel/notifier.c:93
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
discard_slab mm/slub.c:2122 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
put_cpu_partial+0x17c/0x250 mm/slub.c:2738
__slab_free+0x31d/0x410 mm/slub.c:3686
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3530
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
alloc_skb include/linux/skbuff.h:1284 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1194 [inline]
netlink_sendmsg+0x65b/0xbe0 net/netlink/af_netlink.c:1879
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x46a/0x620 net/socket.c:2201
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xde/0xf0 net/socket.c:2209
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
Memory state around the buggy address:
ffff888030125100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888030125180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888030125200: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888030125280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888030125300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
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syzbot
Jul 25, 2025, 10:33:28 PM7/25/25
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: dbcb8d8e4163 Linux 6.6.100
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1384d4f0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=293251cfa8d8100
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=137688a2580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d0b56817a2c3/disk-dbcb8d8e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0d646b2f7fa/vmlinux-dbcb8d8e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1e0b752a5011/bzImage-dbcb8d8e.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/aa4da5e8eba8/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+310389...@syzkaller.appspotmail.com
syz.0.16[5950]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set
loop0: detected capacity change from 0 to 1024
CPU: 1 PID: 5950 Comm: syz.0.16 Not tainted 6.6.100-syzkaller #0
RAX: ffffffffffffffda RBX: 00007ff62dfb5fa0 RCX: 00007ff62dd8e9a9
</TASK>
Allocated by task 5950:
The buggy address belongs to the physical page:
page:ffffea0001e83a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807a0ef000 pfn:0x7a0e8
head:ffffea0001e83a00 order:3 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 ffff888017841dc0 0000000000000000 0000000000000001
raw: ffff88807a0ef000 000000008010000e 00000001ffffffff 0000000000000000
kmalloc include/linux/slab.h:604 [inline]
load_elf_phdrs fs/binfmt_elf.c:512 [inline]
load_elf_binary+0x2cd/0x2700 fs/binfmt_elf.c:886
search_binary_handler fs/exec.c:1775 [inline]
exec_binprm fs/exec.c:1817 [inline]
bprm_execve+0xaeb/0x16f0 fs/exec.c:1892
do_execveat_common+0x51b/0x6c0 fs/exec.c:1998
do_execve fs/exec.c:2072 [inline]
__do_sys_execve fs/exec.c:2148 [inline]
__se_sys_execve fs/exec.c:2143 [inline]
__x64_sys_execve+0x92/0xa0 fs/exec.c:2143
__kmem_cache_alloc_lru mm/slub.c:3500 [inline]
kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
vm_area_alloc+0x24/0x1d0 kernel/fork.c:486
__mmap_region mm/mmap.c:2766 [inline]
mmap_region+0xbe6/0x1f80 mm/mmap.c:2937
do_mmap+0x8d1/0xfd0 mm/mmap.c:1381
vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556
ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1427
ffff88807a0ea980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807a0eaa00: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88807a0eaa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807a0eab00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: dbcb8d8e4163 Linux 6.6.100
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1384d4f0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=293251cfa8d8100
dashboard link: https://syzkaller.appspot.com/bug?extid=310389f7e95350930d25
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12840782580000
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=137688a2580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d0b56817a2c3/disk-dbcb8d8e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0d646b2f7fa/vmlinux-dbcb8d8e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1e0b752a5011/bzImage-dbcb8d8e.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/aa4da5e8eba8/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+310389...@syzkaller.appspotmail.com
loop0: detected capacity change from 0 to 1024
==================================================================
BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
Read of size 2 at addr ffff88807a0eaa18 by task syz.0.16/5950
BUG: KASAN: slab-out-of-bounds in hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
CPU: 1 PID: 5950 Comm: syz.0.16 Not tainted 6.6.100-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/0x200 mm/kasan/report.c:466
kasan_report+0x117/0x150 mm/kasan/report.c:579
hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
hfsplus_listxattr+0x58f/0xb80 fs/hfsplus/xattr.c:736
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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: 0033:0x7ff62dd8e9a9
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/0x200 mm/kasan/report.c:466
kasan_report+0x117/0x150 mm/kasan/report.c:579
hfsplus_uni2asc+0x595/0x1210 fs/hfsplus/unicode.c:179
hfsplus_listxattr+0x58f/0xb80 fs/hfsplus/xattr.c:736
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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
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:00007ffedcbd9ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3
RAX: ffffffffffffffda RBX: 00007ff62dfb5fa0 RCX: 00007ff62dd8e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007ff62de10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff62dfb5fa0 R14: 00007ff62dfb5fa0 R15: 0000000000000003
</TASK>
Allocated by task 5950:
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+0xb4/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
hfsplus_find_init+0x89/0x1d0 fs/hfsplus/bfind.c:21
hfsplus_listxattr+0x390/0xb80 fs/hfsplus/xattr.c:695
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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 ffff88807a0ea800
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+0xb4/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
hfsplus_find_init+0x89/0x1d0 fs/hfsplus/bfind.c:21
hfsplus_listxattr+0x390/0xb80 fs/hfsplus/xattr.c:695
vfs_listxattr fs/xattr.c:494 [inline]
listxattr+0x107/0x280 fs/xattr.c:842
path_listxattr+0xdd/0x1b0 fs/xattr.c:866
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
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes to the right of
allocated 536-byte region [ffff88807a0ea800, ffff88807a0eaa18)
The buggy address is located 0 bytes to the right of
The buggy address belongs to the physical page:
head:ffffea0001e83a00 order:3 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 ffff888017841dc0 0000000000000000 0000000000000001
raw: ffff88807a0ef000 000000008010000e 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5709, tgid 5709 (dhcpcd-run-hook), ts 64685927589, free_ts 64633529327
page_owner tracks the page as allocated
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+0xa4/0x240 mm/slab_common.c:1020
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 include/linux/slab.h:604 [inline]
load_elf_phdrs fs/binfmt_elf.c:512 [inline]
load_elf_binary+0x2cd/0x2700 fs/binfmt_elf.c:886
search_binary_handler fs/exec.c:1775 [inline]
exec_binprm fs/exec.c:1817 [inline]
bprm_execve+0xaeb/0x16f0 fs/exec.c:1892
do_execveat_common+0x51b/0x6c0 fs/exec.c:1998
do_execve fs/exec.c:2072 [inline]
__do_sys_execve fs/exec.c:2148 [inline]
__se_sys_execve fs/exec.c:2143 [inline]
__x64_sys_execve+0x92/0xa0 fs/exec.c:2143
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
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
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
discard_slab mm/slub.c:2122 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
put_cpu_partial+0x17c/0x250 mm/slub.c:2738
__slab_free+0x31d/0x410 mm/slub.c:3686
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
slab_alloc mm/slub.c:3493 [inline]
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
discard_slab mm/slub.c:2122 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
put_cpu_partial+0x17c/0x250 mm/slub.c:2738
__slab_free+0x31d/0x410 mm/slub.c:3686
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
__kmem_cache_alloc_lru mm/slub.c:3500 [inline]
kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
vm_area_alloc+0x24/0x1d0 kernel/fork.c:486
__mmap_region mm/mmap.c:2766 [inline]
mmap_region+0xbe6/0x1f80 mm/mmap.c:2937
do_mmap+0x8d1/0xfd0 mm/mmap.c:1381
vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556
ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1427
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
Memory state around the buggy address:
ffff88807a0ea900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88807a0ea980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807a0eaa00: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88807a0eaa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807a0eab00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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