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:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=0DGWtEl1DY5MxpGg2Om25EwGEhrBnSighO6L+1vhr+4=; b=bVM0/Zn7Wpl194GERUCeZ0/Mc9klS6hiNzSmCbyF4hhVEOqrhimmGgmPGqdu5ZBpya ky5GvTulPxv/42R9kEx4gZ7sCPjR2AXDr3kMzUai5ZsyQj30WBlJpRh5ONEdZpXUbIqH xt/PnKHyFORE1JNSjjZ4WXmLIGLxbB9CkLWDjqsQvEUAGEWQ+3LzjaGGPR4nUgK70TD6 X39ZtOmtfep7AufOVNIVSKBD3N84WtdVQsGvdk2GJUWAoNFQogI3nqIypbMqN+yuKMgA 5jMQ0qbAzDqWfNtFLGPc+/svF2kGJRGWah64tvOiU12aZZza8Kc7Oofa9nc0GDyZVNE/ tr9g== X-Gm-Message-State: AOJu0YziErjeq8XTJo9Ub3ryI3LcyUKcKHACsnJ7FuwWGDTDngjYW9ap fjHDhtuUJKXRmMfN4vL0xWDXxUlQRJ9/0S5nDUo0xRlGyUEZIkzg+yYOY4ezGbXlD1qKhem1Eot ss7+PZaptXSIyxQ36VrHD0aIysbvMalVI3uQiVTj/WdAlc8yrtDUQO3y2PbP81w== Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4b14:b0:6a3:927:a1d4 with SMTP id 006d021491bc7-6ae96f2a7b4mr5127081eaf.24.1785969877007; Wed, 05 Aug 2026 15:44:37 -0700 (PDT) Date: Wed, 05 Aug 2026 15:44:36 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a73bcd4.01d0871a.3a0d52.0002.GAE@google.com> Subject: [syzbot] [media?] KASAN: slab-use-after-free Read in rc_dev_uevent From: syzbot To: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org, sean@mess.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 848acc8ffe1b Merge tag 'fsverity-for-linus' of git://git.k.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=104093b9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=145fa60d73086782 dashboard link: https://syzkaller.appspot.com/bug?extid=237c754233330b2bf565 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=144bacc6580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1399fc9e580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/32c9dc084aaa/disk-848acc8f.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b7604244b0a9/vmlinux-848acc8f.xz kernel image: https://storage.googleapis.com/syzbot-assets/4cd321f6fe47/bzImage-848acc8f.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+237c754233330b2bf565@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:648 [inline] BUG: KASAN: slab-use-after-free in string+0x471/0x4d0 lib/vsprintf.c:730 Read of size 1 at addr ffff88807aced758 by task udevd/4977 CPU: 1 UID: 0 PID: 4977 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 string_nocheck lib/vsprintf.c:648 [inline] string+0x471/0x4d0 lib/vsprintf.c:730 vsnprintf+0x422/0x1300 lib/vsprintf.c:2945 add_uevent_var+0x183/0x3a0 lib/kobject_uevent.c:682 rc_dev_uevent+0x17d/0x1c0 drivers/media/rc/rc-main.c:1632 dev_uevent+0x2f1/0x870 drivers/base/core.c:2779 uevent_show+0x1ca/0x3a0 drivers/base/core.c:2826 dev_attr_show+0x52/0xa0 drivers/base/core.c:2487 sysfs_kf_seq_show+0x217/0x3f0 fs/sysfs/file.c:65 seq_read_iter+0x32f/0x1270 fs/seq_file.c:231 kernfs_fop_read_iter+0x46c/0x610 fs/kernfs/file.c:290 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x82e/0xb40 fs/read_write.c:574 ksys_read+0x12a/0x250 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f168bca7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffda5a592a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f168c37c880 RCX: 00007f168bca7407 RDX: 0000000000001000 RSI: 0000557455235f80 RDI: 000000000000000c RBP: 00007f168bdefff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f168bdefea0 R14: 0000000000000000 R15: 0000557455215a60 Allocated by task 1222: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5489 _kmalloc_noprof include/linux/slab.h:988 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] redrat3_dev_probe+0x326/0x2b50 drivers/media/rc/redrat3.c:1023 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3772 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3772 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x30a3/0x4a60 drivers/usb/core/hub.c:5953 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 1222: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x22b/0x6c0 mm/slub.c:6692 redrat3_delete drivers/media/rc/redrat3.c:466 [inline] redrat3_dev_probe+0x107a/0x2b50 drivers/media/rc/redrat3.c:1124 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3772 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3772 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x30a3/0x4a60 drivers/usb/core/hub.c:5953 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88807aced000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1880 bytes inside of freed 2048-byte region [ffff88807aced000, ffff88807aced800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ace8 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 ffff88813fe28000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe28000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 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 4966, tgid 4966 (klogd), ts 87973202656, free_ts 87882599427 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab mm/slub.c:3380 [inline] new_slab+0xa2/0x640 mm/slub.c:3426 refill_objects+0xe3/0x410 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __kmalloc_cache_noprof+0x479/0x6c0 mm/slub.c:5485 _kmalloc_noprof include/linux/slab.h:988 [inline] syslog_print+0xf8/0x620 kernel/printk/printk.c:1585 do_syslog+0x5bd/0x6d0 kernel/printk/printk.c:1763 __do_sys_syslog kernel/printk/printk.c:1855 [inline] __se_sys_syslog kernel/printk/printk.c:1853 [inline] __x64_sys_syslog+0x74/0xb0 kernel/printk/printk.c:1853 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 4977 tgid 4977 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931 alloc_filename fs/namei.c:147 [inline] do_getname+0x35/0x390 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2566 [inline] do_sys_openat2+0xc7/0x1e0 fs/open.c:1367 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807aced600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807aced680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807aced700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807aced780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807aced800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup