[v5.15] KASAN: use-after-free Read in rose_transmit_link

Hello,

syzbot found the following issue on:

HEAD commit: 16fdf2c7111b Linux 5.15.181
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12db20f4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1748ac0065c72647
dashboard link: https://syzkaller.appspot.com/bug?extid=84ac815d6e53a68f443f
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d8540163643f/disk-16fdf2c7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1a4c570bb8bc/vmlinux-16fdf2c7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d4ed683eba5e/bzImage-16fdf2c7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

==================================================================
BUG: KASAN: use-after-free in rose_transmit_link+0x5b0/0x730 net/rose/rose_link.c:266
Read of size 1 at addr ffff888079b43c32 by task syz.4.37/4406

CPU: 1 PID: 4406 Comm: syz.4.37 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
print_address_description+0x60/0x2d0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0xdf/0x130 mm/kasan/report.c:451
rose_transmit_link+0x5b0/0x730 net/rose/rose_link.c:266
rose_write_internal+0x673/0x1e80 net/rose/rose_subr.c:198
rose_release+0x22a/0x4e0 net/rose/af_rose.c:670
__sock_release net/socket.c:649 [inline]
sock_close+0xd5/0x240 net/socket.c:1336
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
get_signal+0x1222/0x12c0 kernel/signal.c:2672
arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9c60ef1969
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:00007f9c5ed38038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffe00 RBX: 00007f9c61119080 RCX: 00007f9c60ef1969
RDX: 000000000000001c RSI: 0000200000000240 RDI: 0000000000000007
RBP: 00007f9c60f73ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9c61119080 R15: 00007ffeb5cea938
</TASK>

Allocated by task 4349:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
kmalloc include/linux/slab.h:604 [inline]
rose_add_node+0x227/0xdb0 net/rose/rose_route.c:85
rose_rt_ioctl+0x9db/0xe20 net/rose/rose_route.c:745
rose_ioctl+0x27a/0x790 net/rose/af_rose.c:1372
sock_do_ioctl+0xd3/0x2f0 net/socket.c:1140
sock_ioctl+0x4ed/0x6e0 net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 4409:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1705 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731
slab_free mm/slub.c:3499 [inline]
kfree+0xef/0x2a0 mm/slub.c:4559
rose_rt_device_down+0x3e5/0x430 net/rose/rose_route.c:522
rose_device_event+0x5ec/0x680 net/rose/af_rose.c:247
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1
dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929
dev_ifsioc+0x147/0xe70 net/core/dev_ioctl.c:324
dev_ioctl+0x55f/0xe50 net/core/dev_ioctl.c:587
sock_do_ioctl+0x222/0x2f0 net/socket.c:1154
sock_ioctl+0x4ed/0x6e0 net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888079b43c00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 50 bytes inside of
512-byte region [ffff888079b43c00, ffff888079b43e00)
The buggy address belongs to the page:
page:ffffea0001e6d000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79b40
head:ffffea0001e6d000 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888016841c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3548, ts 22631255200, free_ts 19490651408
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
__alloc_pages+0x1e1/0x470 mm/page_alloc.c:5466
alloc_slab_page mm/slub.c:1775 [inline]
allocate_slab mm/slub.c:1912 [inline]
new_slab+0xc0/0x4b0 mm/slub.c:1975
___slab_alloc+0x81e/0xdf0 mm/slub.c:3008
__slab_alloc mm/slub.c:3095 [inline]
slab_alloc_node mm/slub.c:3186 [inline]
__kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4958
kmalloc_reserve net/core/skbuff.c:356 [inline]
__alloc_skb+0x22c/0x750 net/core/skbuff.c:427
alloc_skb include/linux/skbuff.h:1162 [inline]
alloc_uevent_skb+0x7d/0x230 lib/kobject_uevent.c:290
uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline]
kobject_uevent_net_broadcast+0x2e6/0x530 lib/kobject_uevent.c:409
kobject_uevent_env+0x556/0x890 lib/kobject_uevent.c:608
kobject_synth_uevent+0x520/0xaf0 lib/kobject_uevent.c:208
uevent_store+0x48/0x70 drivers/base/bus.c:583
kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2172 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
free_unref_page+0x94/0x280 mm/page_alloc.c:3396
free_contig_range+0x96/0xf0 mm/page_alloc.c:9385
destroy_args+0xef/0x8b0 mm/debug_vm_pgtable.c:1018
debug_vm_pgtable+0x318/0x370 mm/debug_vm_pgtable.c:1331
do_one_initcall+0x1ee/0x680 init/main.c:1302
do_initcall_level+0x137/0x1f0 init/main.c:1375
do_initcalls+0x4b/0x90 init/main.c:1391
kernel_init_freeable+0x3ce/0x560 init/main.c:1615
kernel_init+0x19/0x1b0 init/main.c:1506
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
ffff888079b43b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888079b43b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888079b43c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888079b43c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888079b43d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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HEAD commit: ac7079a42ea5 Linux 6.1.137
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=102568f4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b6c9ee6fabde22af
dashboard link: https://syzkaller.appspot.com/bug?extid=91aa0b1c9fd9835feb0f
disk image: https://storage.googleapis.com/syzbot-assets/235ed7912afd/disk-ac7079a4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/66591056046a/vmlinux-ac7079a4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/11e3c8def63d/bzImage-ac7079a4.xz
Reported-by: [email protected]

==================================================================
BUG: KASAN: use-after-free in rose_transmit_link+0x5b6/0x730 net/rose/rose_link.c:266
Read of size 1 at addr ffff888057a13032 by task syz.1.2640/13277

CPU: 1 PID: 13277 Comm: syz.1.2640 Not tainted 6.1.137-syzkaller #0
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
print_address_description mm/kasan/report.c:316 [inline]
print_report+0xa8/0x220 mm/kasan/report.c:427
kasan_report+0x10b/0x140 mm/kasan/report.c:531
rose_transmit_link+0x5b6/0x730 net/rose/rose_link.c:266
rose_write_internal+0x1096/0x1eb0 net/rose/rose_subr.c:198
rose_release+0x22a/0x4f0 net/rose/af_rose.c:671
__sock_release net/socket.c:654 [inline]
sock_close+0xd5/0x240 net/socket.c:1400
__fput+0x22c/0x920 fs/file_table.c:320
task_work_run+0x1ca/0x250 kernel/task_work.c:203
get_signal+0x11a6/0x1350 kernel/signal.c:2648
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe19878e969
RSP: 002b:00007fe1985ff038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffe00 RBX: 00007fe1989b5fa0 RCX: 00007fe19878e969
RDX: 000000000000001c RSI: 0000200000000240 RDI: 0000000000000005
RBP: 00007fe198810ab1 R08: 0000000000000000 R09: 0000000000000000
R13: 0000000000000000 R14: 00007fe1989b5fa0 R15: 00007fff7cc728f8
</TASK>

Allocated by task 10823:
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
kmalloc include/linux/slab.h:563 [inline]
rose_add_node+0x227/0xdb0 net/rose/rose_route.c:85
rose_rt_ioctl+0xa4c/0xe90 net/rose/rose_route.c:747
rose_ioctl+0x27a/0x790 net/rose/af_rose.c:1380
sock_do_ioctl+0xd3/0x2f0 net/socket.c:1204
sock_ioctl+0x4ed/0x6e0 net/socket.c:1321
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
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

Freed by task 13282:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1724 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750
slab_free mm/slub.c:3661 [inline]
__kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674
rose_rt_device_down+0x3e5/0x430 net/rose/rose_route.c:522
rose_device_event+0x600/0x690 net/rose/af_rose.c:248
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
dev_ifsioc+0x159/0xe90 net/core/dev_ioctl.c:327
dev_ioctl+0x578/0xea0 net/core/dev_ioctl.c:588
sock_do_ioctl+0x222/0x2f0 net/socket.c:1218
sock_ioctl+0x4ed/0x6e0 net/socket.c:1321
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
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 ffff888057a13000
512-byte region [ffff888057a13000, ffff888057a13200)

The buggy address belongs to the physical page:
page:ffffea00015e8400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888057a10000 pfn:0x57a10
head:ffffea00015e8400 order:2 compound_mapcount:0 compound_pincount:0
raw: 00fff00000010200 ffffea0001674108 ffffea00015fd808 ffff888017441c80
raw: ffff888057a10000 0000000000100004 00000001ffffffff 0000000000000000
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4262, tgid 4262 (syz-executor), ts 65027868248, free_ts 16919987891
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:5606
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
__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956
kmalloc_reserve net/core/skbuff.c:446 [inline]
__alloc_skb+0x22a/0x7e0 net/core/skbuff.c:515
alloc_skb include/linux/skbuff.h:1271 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline]
netlink_sendmsg+0x645/0xbc0 net/netlink/af_netlink.c:1834
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
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
free_contig_range+0x9d/0x150 mm/page_alloc.c:9566
destroy_args+0xef/0x8bf mm/debug_vm_pgtable.c:1031
debug_vm_pgtable+0x32a/0x37e mm/debug_vm_pgtable.c:1354
do_one_initcall+0x214/0x7a0 init/main.c:1298
do_initcall_level+0x137/0x1e4 init/main.c:1371
do_initcalls+0x4b/0x8a init/main.c:1387
kernel_init_freeable+0x3fa/0x5ac init/main.c:1626
kernel_init+0x19/0x1b0 init/main.c:1514
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
ffff888057a12f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888057a12f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888057a13000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888057a13080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888057a13100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb