[syzbot] [media?] KASAN: slab-use-after-free Read in vidtv_mux_init

From: syzbot
Date: Mon Mar 10 2025 - 09:32:34 EST

Next message: Koichiro Den: "Re: [PATCH v5 0/9] Introduce configfs-based interface for gpio-aggregator"
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Hello,

syzbot found the following issue on:

HEAD commit: 848e07631744 Merge tag 'hid-for-linus-2025030501' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12e38a64580000
kernel config: https://syzkaller.appspot.com/x/.config?x=bed8205d3b84ef81
dashboard link: https://syzkaller.appspot.com/bug?extid=0d33ab192bd50b6c91e6
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=138afda8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6a6c7015dd03/disk-848e0763.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/66cbd3af2068/vmlinux-848e0763.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1c1ceeb2230c/bzImage-848e0763.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0d33ab192bd50b6c91e6@xxxxxxxxxxxxxxxxxxxxxxxxx

RBP: 00007fff4b19a7ec R08: 0000000b4b19a87f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000003
R13: 00000000000927c0 R14: 000000000001d553 R15: 00007fff4b19a840
</TASK>
==================================================================
BUG: KASAN: slab-use-after-free in vidtv_mux_pid_ctx_init drivers/media/test-drivers/vidtv/vidtv_mux.c:78 [inline]
BUG: KASAN: slab-use-after-free in vidtv_mux_init+0xac2/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:524
Read of size 8 at addr ffff88802fa42acc by task syz.2.37/6059

CPU: 0 UID: 0 PID: 6059 Comm: syz.2.37 Not tainted 6.14.0-rc5-syzkaller-00039-g848e07631744 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xd9/0x110 mm/kasan/report.c:634
vidtv_mux_pid_ctx_init drivers/media/test-drivers/vidtv/vidtv_mux.c:78 [inline]
vidtv_mux_init+0xac2/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:524
vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline]
vidtv_start_feed+0x334/0x4c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239
dmx_section_feed_start_filtering+0x3a5/0x660 drivers/media/dvb-core/dvb_demux.c:973
dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline]
dvb_dmxdev_feed_restart.isra.0+0x457/0x530 drivers/media/dvb-core/dmxdev.c:537
dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564
dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline]
dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246
__fput+0x3ff/0xb70 fs/file_table.c:464
task_work_run+0x14e/0x250 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0xad8/0x2d70 kernel/exit.c:938
do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
__do_sys_exit_group kernel/exit.c:1098 [inline]
__se_sys_exit_group kernel/exit.c:1096 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f871d58d169
Code: Unable to access opcode bytes at 0x7f871d58d13f.
RSP: 002b:00007fff4b19a788 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f871d58d169
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff4b19a7ec R08: 0000000b4b19a87f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000003
R13: 00000000000927c0 R14: 000000000001d553 R15: 00007fff4b19a840
</TASK>

Allocated by task 6059:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
vidtv_psi_pat_table_init+0x46/0x2c0 drivers/media/test-drivers/vidtv/vidtv_psi.c:970
vidtv_channel_si_init+0x67/0x1a90 drivers/media/test-drivers/vidtv/vidtv_channel.c:423
vidtv_mux_init+0x526/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:519
vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline]
vidtv_start_feed+0x334/0x4c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239
dmx_section_feed_start_filtering+0x3a5/0x660 drivers/media/dvb-core/dvb_demux.c:973
dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline]
dvb_dmxdev_feed_restart.isra.0+0x457/0x530 drivers/media/dvb-core/dmxdev.c:537
dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564
dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline]
dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246
__fput+0x3ff/0xb70 fs/file_table.c:464
task_work_run+0x14e/0x250 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0xad8/0x2d70 kernel/exit.c:938
do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
__do_sys_exit_group kernel/exit.c:1098 [inline]
__se_sys_exit_group kernel/exit.c:1096 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6059:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2353 [inline]
slab_free mm/slub.c:4609 [inline]
kfree+0x2c4/0x4d0 mm/slub.c:4757
vidtv_channel_si_init+0x34a/0x1a90 drivers/media/test-drivers/vidtv/vidtv_channel.c:499
vidtv_mux_init+0x526/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:519
vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline]
vidtv_start_feed+0x334/0x4c0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239
dmx_section_feed_start_filtering+0x3a5/0x660 drivers/media/dvb-core/dvb_demux.c:973
dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline]
dvb_dmxdev_feed_restart.isra.0+0x457/0x530 drivers/media/dvb-core/dmxdev.c:537
dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564
dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline]
dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246
__fput+0x3ff/0xb70 fs/file_table.c:464
task_work_run+0x14e/0x250 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0xad8/0x2d70 kernel/exit.c:938
do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
__do_sys_exit_group kernel/exit.c:1098 [inline]
__se_sys_exit_group kernel/exit.c:1096 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802fa42ac0
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 12 bytes inside of
freed 32-byte region [ffff88802fa42ac0, ffff88802fa42ae0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2fa42
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b041780 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000400040 00000000f5000000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5963, tgid 5963 (syz-executor), ts 120407289997, free_ts 120403969520
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
prep_new_page mm/page_alloc.c:1559 [inline]
get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477
__alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739
alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:2423 [inline]
allocate_slab mm/slub.c:2587 [inline]
new_slab+0x23d/0x330 mm/slub.c:2640
___slab_alloc+0xc5d/0x1720 mm/slub.c:3826
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916
__slab_alloc_node mm/slub.c:3991 [inline]
slab_alloc_node mm/slub.c:4152 [inline]
__kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
ref_tracker_alloc+0x17c/0x5b0 lib/ref_tracker.c:203
__netdev_tracker_alloc include/linux/netdevice.h:4282 [inline]
netdev_tracker_alloc include/linux/netdevice.h:4294 [inline]
netdev_get_by_index+0x7c/0xb0 net/core/dev.c:990
fib6_nh_init+0x792/0x1da0 net/ipv6/route.c:3548
ip6_route_info_create+0x1073/0x1910 net/ipv6/route.c:3814
ip6_route_add+0x26/0x1c0 net/ipv6/route.c:3858
addrconf_add_mroute+0x1de/0x350 net/ipv6/addrconf.c:2549
addrconf_add_dev+0x14e/0x1c0 net/ipv6/addrconf.c:2567
addrconf_dev_config net/ipv6/addrconf.c:3475 [inline]
addrconf_init_auto_addrs+0x380/0x820 net/ipv6/addrconf.c:3563
page last free pid 6059 tgid 6059 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660
tlb_batch_list_free mm/mmu_gather.c:159 [inline]
tlb_finish_mmu+0x237/0x7b0 mm/mmu_gather.c:491
exit_mmap+0x40e/0xba0 mm/mmap.c:1297
__mmput+0x12a/0x410 kernel/fork.c:1356
mmput+0x62/0x70 kernel/fork.c:1378
exit_mm kernel/exit.c:570 [inline]
do_exit+0x9ba/0x2d70 kernel/exit.c:925
do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
__do_sys_exit_group kernel/exit.c:1098 [inline]
__se_sys_exit_group kernel/exit.c:1096 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff88802fa42980: 00 00 00 05 fc fc fc fc 00 00 05 fc fc fc fc fc
ffff88802fa42a00: 00 00 02 fc fc fc fc fc 00 00 00 00 fc fc fc fc
>ffff88802fa42a80: 00 00 00 04 fc fc fc fc fa fb fb fb fc fc fc fc
^
ffff88802fa42b00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
ffff88802fa42b80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================

---
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Next message: Koichiro Den: "Re: [PATCH v5 0/9] Introduce configfs-based interface for gpio-aggregator"
Previous message: Ashley Smith: "[PATCH v2] drm/panthor: Make the timeout per-queue instead of per-job"
Next in thread: Edward Adam Davis: "[PATCH] media/vidtv: Terminating the subsequent process of initialization failure"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]