loop1: detected capacity change from 0 to 512 ================================================================== BUG: KASAN: use-after-free in dvb_device_open+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:109 Read of size 8 at addr ffff88814bcd7c18 by task syz.1.2167/29307 CPU: 0 PID: 29307 Comm: syz.1.2167 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:109 chrdev_open+0x5c5/0x6a0 fs/char_dev.c:414 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 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: 0033:0x7f567110304e 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:00007f566f39bb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f566f39c6c0 RCX: 00007f567110304e RDX: 0000000000040002 RSI: 00007f566f39bc00 RDI: ffffffffffffff9c RBP: 00007f566f39bc00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f56713bc038 R14: 00007f56713bbfa0 R15: 00007ffca6cfbb58 Allocated by task 13228: 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_array include/linux/slab.h:647 [inline] kcalloc include/linux/slab.h:676 [inline] __list_lru_init+0xab/0xa50 mm/list_lru.c:596 alloc_super+0x76c/0x950 fs/super.c:272 sget_fc+0x2dc/0x720 fs/super.c:554 vfs_get_super fs/super.c:1167 [inline] get_tree_keyed+0x58/0x190 fs/super.c:1228 vfs_get_tree+0x88/0x270 fs/super.c:1530 vfs_fsconfig_locked+0x22f/0x3f0 fs/fsopen.c:238 __do_sys_fsconfig fs/fsopen.c:445 [inline] __se_sys_fsconfig+0x65a/0x790 fs/fsopen.c:320 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 ffff88814bcd7c00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff88814bcd7c00, ffff88814bcd7d00) The buggy address belongs to the page: page:ffffea00052f3580 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88814bcd7c00 pfn:0x14bcd6 head:ffffea00052f3580 order:1 compound_mapcount:0 flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000010200 ffffea000510ff88 ffffea00052f3b08 ffff888016c41b40 raw: ffff88814bcd7c00 000000000010000f 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 10502085051, free_ts 0 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 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+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node+0x200/0x3b0 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+0x14a/0x950 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+0x2a37/0x3460 drivers/media/test-drivers/vivid/vivid-ctrls.c:1921 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1860 [inline] vivid_probe+0x3c47/0x67a0 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+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 page_owner free stack trace missing Memory state around the buggy address: ffff88814bcd7b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88814bcd7b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88814bcd7c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88814bcd7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88814bcd7d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================