================================================================== BUG: KASAN: use-after-free in dvb_device_open+0xc5/0x360 drivers/media/dvb-core/dvbdev.c:109 Read of size 8 at addr ffff88814c721c18 by task syz.2.1083/7937 CPU: 0 PID: 7937 Comm: syz.2.1083 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 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 dvb_device_open+0xc5/0x360 drivers/media/dvb-core/dvbdev.c:109 chrdev_open+0x585/0x5f0 fs/char_dev.c:414 do_dentry_open+0x7f7/0xf90 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2718/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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 RIP: 0033:0x7fe3c5a7b90e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007fe3c3cd0b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe3c3cd16c0 RCX: 00007fe3c5a7b90e RDX: 0000000000040002 RSI: 00007fe3c3cd0c00 RDI: ffffffffffffff9c RBP: 00007fe3c3cd0c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fe3c5d43218 R14: 00007fe3c5d43180 R15: 00007ffe3c514598 Allocated by task 7781: 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+0xaf/0xe0 mm/kasan/common.c:522 copy_array kernel/bpf/verifier.c:778 [inline] copy_verifier_state+0xe0/0xd00 kernel/bpf/verifier.c:959 is_state_visited kernel/bpf/verifier.c:11117 [inline] do_check+0x369a/0xefc0 kernel/bpf/verifier.c:11232 do_check_common+0xe7f/0x16e0 kernel/bpf/verifier.c:13516 do_check_main kernel/bpf/verifier.c:13579 [inline] bpf_check+0x88c1/0xf6b0 kernel/bpf/verifier.c:14150 bpf_prog_load+0xfdf/0x14e0 kernel/bpf/syscall.c:2354 __sys_bpf+0x532/0x6f0 kernel/bpf/syscall.c:4657 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline] __se_sys_bpf kernel/bpf/syscall.c:4759 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759 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 7781: 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:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 clear_jmp_history kernel/bpf/verifier.c:919 [inline] free_verifier_state+0x1a3/0x230 kernel/bpf/verifier.c:933 is_state_visited kernel/bpf/verifier.c:11066 [inline] do_check+0x1bf5/0xefc0 kernel/bpf/verifier.c:11232 do_check_common+0xe7f/0x16e0 kernel/bpf/verifier.c:13516 do_check_main kernel/bpf/verifier.c:13579 [inline] bpf_check+0x88c1/0xf6b0 kernel/bpf/verifier.c:14150 bpf_prog_load+0xfdf/0x14e0 kernel/bpf/syscall.c:2354 __sys_bpf+0x532/0x6f0 kernel/bpf/syscall.c:4657 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline] __se_sys_bpf kernel/bpf/syscall.c:4759 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759 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 ffff88814c721c00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff88814c721c00, ffff88814c721d00) The buggy address belongs to the page: page:ffffea000531c800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14c720 head:ffffea000531c800 order:1 compound_mapcount:0 flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000010200 0000000000000000 0000000100000001 ffff888016c41b40 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 21257970145, free_ts 0 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node+0x142/0x3a0 mm/slub.c:4456 kmalloc_node include/linux/slab.h:630 [inline] kvmalloc_node+0x84/0x130 mm/util.c:619 kvmalloc include/linux/mm.h:816 [inline] kvzalloc include/linux/mm.h:824 [inline] v4l2_ctrl_new+0x70f/0x1310 drivers/media/v4l2-core/v4l2-ctrls-core.c:1306 v4l2_ctrl_new_std+0x247/0x300 drivers/media/v4l2-core/v4l2-ctrls-core.c:1429 handler_new_ref+0x14f/0x8d0 drivers/media/v4l2-core/v4l2-ctrls-core.c:1098 v4l2_ctrl_add_handler+0x197/0x280 drivers/media/v4l2-core/v4l2-ctrls-core.c:1573 vivid_create_controls+0x2411/0x3380 drivers/media/test-drivers/vivid/vivid-ctrls.c:1875 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1860 [inline] vivid_probe+0x39ff/0x6240 drivers/media/test-drivers/vivid/vivid-core.c:2031 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x276/0xc70 drivers/base/dd.c:595 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775 page_owner free stack trace missing Memory state around the buggy address: ffff88814c721b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88814c721b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88814c721c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88814c721c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88814c721d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================