Hello,
syzbot found the following issue on:
HEAD commit: 01f95500a162 Merge tag 'uml-for-linux-6.15-rc6' of git://g..
git tree: upstream
console output:
https://syzkaller.appspot.com/x/log.txt?x=15bf539b980000
kernel config:
https://syzkaller.appspot.com/x/.config?x=91c351a0f6229e67
dashboard link:
https://syzkaller.appspot.com/bug?extid=0d2ff77d669671a47650
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
userspace arch: i386
CC: [
linux-...@vger.kernel.org linux...@vger.kernel.org mch...@kernel.org]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/ccfa7970676d/disk-01f95500.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/895413221f27/vmlinux-01f95500.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/aabfc5fe1060/bzImage-01f95500.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+0d2ff7...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-use-after-free in v4l2_ioctl+0xc7/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:364
Read of size 8 at addr ffff8880559a00c8 by task v4l_id/22422
CPU: 1 UID: 0 PID: 22422 Comm: v4l_id Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xb4/0x290 mm/kasan/report.c:521
kasan_report+0x118/0x150 mm/kasan/report.c:634
v4l2_ioctl+0xc7/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:364
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f805991ad49
Code: 5c c3 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 76 10 48 8b 15 ae 60 0d 00 f7 d8 41 83 c8
RSP: 002b:00007ffe45597838 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffe455979d8 RCX: 00007f805991ad49
RDX: 00007ffe45597840 RSI: 0000000080685600 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffe455979f0 R14: 0000561bf0036670 R15: 00007f8059e7ba80
</TASK>
Allocated by task 5885:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
hackrf_probe+0xda/0x1360 drivers/media/usb/hackrf/hackrf.c:1351
usb_probe_interface+0x641/0xbc0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x26a/0x9a0 drivers/base/dd.c:657
__driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
__device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957
bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462
__device_attach+0x2b8/0x400 drivers/base/dd.c:1029
bus_probe_device+0x185/0x260 drivers/base/bus.c:537
device_add+0x7b6/0xb50 drivers/base/core.c:3692
usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c1/0x390 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x26a/0x9a0 drivers/base/dd.c:657
__driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
__device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957
bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462
__device_attach+0x2b8/0x400 drivers/base/dd.c:1029
bus_probe_device+0x185/0x260 drivers/base/bus.c:537
device_add+0x7b6/0xb50 drivers/base/core.c:3692
usb_new_device+0xa39/0x16c0 drivers/usb/core/hub.c:2663
hub_port_connect drivers/usb/core/hub.c:5531 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
port_event drivers/usb/core/hub.c:5831 [inline]
hub_event+0x2941/0x4a00 drivers/usb/core/hub.c:5913
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Freed by task 5885:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kfree+0x193/0x440 mm/slub.c:4841
hackrf_probe+0xd98/0x1360 drivers/media/usb/hackrf/hackrf.c:1523
usb_probe_interface+0x641/0xbc0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x26a/0x9a0 drivers/base/dd.c:657
__driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
__device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957
bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462
__device_attach+0x2b8/0x400 drivers/base/dd.c:1029
bus_probe_device+0x185/0x260 drivers/base/bus.c:537
device_add+0x7b6/0xb50 drivers/base/core.c:3692
usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c1/0x390 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x26a/0x9a0 drivers/base/dd.c:657
__driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
__device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957
bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462
__device_attach+0x2b8/0x400 drivers/base/dd.c:1029
bus_probe_device+0x185/0x260 drivers/base/bus.c:537
device_add+0x7b6/0xb50 drivers/base/core.c:3692
usb_new_device+0xa39/0x16c0 drivers/usb/core/hub.c:2663
hub_port_connect drivers/usb/core/hub.c:5531 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
port_event drivers/usb/core/hub.c:5831 [inline]
hub_event+0x2941/0x4a00 drivers/usb/core/hub.c:5913
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the object at ffff8880559a0000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 200 bytes inside of
freed 8192-byte region [ffff8880559a0000, ffff8880559a2000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x559a0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a042280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a042280 dead000000000122 0000000000000000
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001566801 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
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 5885, tgid 5885 (kworker/0:4), ts 1276180656067, free_ts 1275706943051
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
prep_new_page mm/page_alloc.c:1726 [inline]
get_page_from_freelist+0x21ce/0x22b0 mm/page_alloc.c:3688
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
alloc_slab_page mm/slub.c:2450 [inline]
allocate_slab+0x8a/0x3b0 mm/slub.c:2618
new_slab mm/slub.c:2672 [inline]
___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
__slab_alloc mm/slub.c:3948 [inline]
__slab_alloc_node mm/slub.c:4023 [inline]
slab_alloc_node mm/slub.c:4184 [inline]
__kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4353
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
hackrf_probe+0xda/0x1360 drivers/media/usb/hackrf/hackrf.c:1351
usb_probe_interface+0x641/0xbc0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x26a/0x9a0 drivers/base/dd.c:657
__driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
__device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957
bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462
__device_attach+0x2b8/0x400 drivers/base/dd.c:1029
bus_probe_device+0x185/0x260 drivers/base/bus.c:537
page last free pid 14368 tgid 14368 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1262 [inline]
__free_frozen_pages+0xb0e/0xcd0 mm/page_alloc.c:2725
discard_slab mm/slub.c:2716 [inline]
__put_partials+0x161/0x1c0 mm/slub.c:3185
put_cpu_partial+0x17c/0x250 mm/slub.c:3260
__slab_free+0x2f7/0x400 mm/slub.c:4512
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4147 [inline]
slab_alloc_node mm/slub.c:4196 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203
alloc_pid+0x9f/0xab0 kernel/pid.c:182
copy_process+0x195b/0x3b80 kernel/fork.c:2445
kernel_clone+0x21e/0x870 kernel/fork.c:2844
__do_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:254 [inline]
__se_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:240 [inline]
__ia32_compat_sys_ia32_clone+0x189/0x1e0 arch/x86/kernel/sys_ia32.c:240
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
Memory state around the buggy address:
ffff88805599ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880559a0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880559a0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880559a0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880559a0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
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