[syzbot] [media?] KASAN: slab-out-of-bounds Read in v4l2_compat_put_array_args (2)

From: syzbot
Date: Wed Apr 19 2023 - 02:49:57 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 95abc817ab3a Merge tag 'acpi-6.3-rc7' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=147a14e7c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=c21559e740385326
dashboard link: https://syzkaller.appspot.com/bug?extid=3cea453754f73db49fa5
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3cea453754f73db49fa5@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: slab-out-of-bounds in instrument_copy_to_user include/linux/instrumented.h:119 [inline]
BUG: KASAN: slab-out-of-bounds in _copy_to_user lib/usercopy.c:40 [inline]
BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x11a/0x150 lib/usercopy.c:34
Read of size 16 at addr ffff88801bd7d658 by task syz-executor.3/15229

CPU: 0 PID: 15229 Comm: syz-executor.3 Not tainted 6.3.0-rc6-syzkaller-00168-g95abc817ab3a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319
print_report mm/kasan/report.c:430 [inline]
kasan_report+0x11c/0x130 mm/kasan/report.c:536
check_region_inline mm/kasan/generic.c:181 [inline]
kasan_check_range+0x141/0x190 mm/kasan/generic.c:187
instrument_copy_to_user include/linux/instrumented.h:119 [inline]
_copy_to_user lib/usercopy.c:40 [inline]
_copy_to_user+0x11a/0x150 lib/usercopy.c:34
copy_to_user include/linux/uaccess.h:169 [inline]
v4l2_compat_put_array_args+0x484/0x830 drivers/media/v4l2-core/v4l2-compat-ioctl32.c:1154
video_usercopy+0x46e/0x15f0 drivers/media/v4l2-core/v4l2-ioctl.c:3435
v4l2_ioctl+0x1b7/0x250 drivers/media/v4l2-core/v4l2-dev.c:364
v4l2_compat_ioctl32+0x23b/0x2a0 drivers/media/v4l2-core/v4l2-compat-ioctl32.c:1253
__do_compat_sys_ioctl+0x255/0x2b0 fs/ioctl.c:968
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x70/0x82
RIP: 0023:0xf7fb7579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f7fb25cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000c0cc5604
RDX: 0000000020000480 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>

Allocated by task 15229:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
____kasan_kmalloc mm/kasan/common.c:333 [inline]
__kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:196 [inline]
__do_kmalloc_node mm/slab_common.c:967 [inline]
__kmalloc_node+0x61/0x1a0 mm/slab_common.c:974
kmalloc_node include/linux/slab.h:610 [inline]
kvmalloc_node+0xa2/0x1a0 mm/util.c:603
kvmalloc include/linux/slab.h:737 [inline]
video_usercopy+0x642/0x15f0 drivers/media/v4l2-core/v4l2-ioctl.c:3386
v4l2_ioctl+0x1b7/0x250 drivers/media/v4l2-core/v4l2-dev.c:364
v4l2_compat_ioctl32+0x23b/0x2a0 drivers/media/v4l2-core/v4l2-compat-ioctl32.c:1253
__do_compat_sys_ioctl+0x255/0x2b0 fs/ioctl.c:968
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x70/0x82

The buggy address belongs to the object at ffff88801bd7d640
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes to the right of
allocated 24-byte region [ffff88801bd7d640, ffff88801bd7d658)

The buggy address belongs to the physical page:
page:ffffea00006f5f40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801bd7d840 pfn:0x1bd7d
ksm flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff888012442500 ffffea000079bb40 dead000000000003
raw: ffff88801bd7d840 0000000080400032 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 28974, tgid 28974 (syz-executor.1), ts 809995593806, free_ts 808146796979
prep_new_page mm/page_alloc.c:2553 [inline]
get_page_from_freelist+0x1190/0x2e20 mm/page_alloc.c:4326
__alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:5592
__alloc_pages_node include/linux/gfp.h:237 [inline]
alloc_slab_page mm/slub.c:1853 [inline]
allocate_slab+0xa7/0x390 mm/slub.c:1998
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0xa91/0x1400 mm/slub.c:3193
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
__slab_alloc_node mm/slub.c:3345 [inline]
slab_alloc_node mm/slub.c:3442 [inline]
__kmem_cache_alloc_node+0x136/0x320 mm/slub.c:3491
__do_kmalloc_node mm/slab_common.c:966 [inline]
__kmalloc_node+0x51/0x1a0 mm/slab_common.c:974
kmalloc_array_node include/linux/slab.h:697 [inline]
kcalloc_node include/linux/slab.h:702 [inline]
memcg_alloc_slab_cgroups+0x8f/0x150 mm/memcontrol.c:2899
account_slab mm/slab.h:653 [inline]
allocate_slab+0x2d6/0x390 mm/slub.c:2016
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0xa91/0x1400 mm/slub.c:3193
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
__slab_alloc_node mm/slub.c:3345 [inline]
slab_alloc_node mm/slub.c:3442 [inline]
kmem_cache_alloc_node+0x138/0x3e0 mm/slub.c:3497
alloc_task_struct_node kernel/fork.c:171 [inline]
dup_task_struct kernel/fork.c:974 [inline]
copy_process+0x3aa/0x7590 kernel/fork.c:2098
kernel_clone+0xeb/0x890 kernel/fork.c:2682
__do_compat_sys_ia32_clone+0x9e/0xd0 arch/x86/kernel/sys_ia32.c:254
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
do_int80_syscall_32+0x4a/0x90 arch/x86/entry/common.c:132
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1454 [inline]
free_pcp_prepare+0x5d5/0xa50 mm/page_alloc.c:1504
free_unref_page_prepare mm/page_alloc.c:3388 [inline]
free_unref_page+0x1d/0x490 mm/page_alloc.c:3483
vfree+0x180/0x7e0 mm/vmalloc.c:2742
delayed_vfree_work+0x57/0x70 mm/vmalloc.c:2663
process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
worker_thread+0x669/0x1090 kernel/workqueue.c:2537
kthread+0x2e8/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Memory state around the buggy address:
ffff88801bd7d500: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
ffff88801bd7d580: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
>ffff88801bd7d600: 00 00 00 00 fc fc fc fc 00 00 00 fc fc fc fc fc
^
ffff88801bd7d680: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
ffff88801bd7d700: fb fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
==================================================================
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 retq
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi

---
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Next message: 沈安琪(凛玥): "Re: [PATCH v8] net/packet: support mergeable feature of virtio"
Previous message: Baolin Wang: "Re: [PATCH] mm/page_alloc: consider pfn holes after pfn_valid() in __pageblock_pfn_to_page()"
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