================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:643 [inline] BUG: KASAN: use-after-free in string+0x39c/0x3d0 lib/vsprintf.c:725 Read of size 1 at addr ffff888079dfa805 by task udevd/20100 CPU: 0 PID: 20100 Comm: udevd Not tainted 6.0.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 string_nocheck lib/vsprintf.c:643 [inline] string+0x39c/0x3d0 lib/vsprintf.c:725 vsnprintf+0x71b/0x14f0 lib/vsprintf.c:2782 add_uevent_var+0x15d/0x380 lib/kobject_uevent.c:665 dev_uevent+0x18d/0x770 drivers/base/core.c:2421 uevent_show+0x1b8/0x380 drivers/base/core.c:2492 dev_attr_show+0x4b/0x90 drivers/base/core.c:2195 sysfs_kf_seq_show+0x219/0x3d0 fs/sysfs/file.c:59 kernfs_seq_show+0x169/0x1e0 fs/kernfs/file.c:217 seq_read_iter+0x4f5/0x1280 fs/seq_file.c:230 kernfs_fop_read_iter+0x523/0x710 fs/kernfs/file.c:299 call_read_iter include/linux/fs.h:2181 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x67d/0x930 fs/read_write.c:470 ksys_read+0x127/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0fe7d258fe Code: c0 e9 e6 fe ff ff 50 48 8d 3d 0e c7 09 00 e8 c9 cf 01 00 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28 RSP: 002b:00007ffce79ec508 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055d54871e740 RCX: 00007f0fe7d258fe RDX: 0000000000001000 RSI: 000055d548763860 RDI: 0000000000000008 RBP: 00007f0fe7df2380 R08: 0000000000000008 R09: 00007f0fe7df5a60 R10: 0000000000000020 R11: 0000000000000246 R12: 000055d54871e740 R13: 0000000000000d68 R14: 00007f0fe7df1780 R15: 0000000000000d68 Allocated by task 20089: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc include/linux/slab.h:600 [inline] raw_ioctl_init+0x152/0x820 drivers/usb/gadget/legacy/raw_gadget.c:460 raw_ioctl+0x8ef/0x2740 drivers/usb/gadget/legacy/raw_gadget.c:1250 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 20098: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1759 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1785 slab_free mm/slub.c:3539 [inline] kfree+0xe2/0x580 mm/slub.c:4567 dev_free+0x9a/0x700 drivers/usb/gadget/legacy/raw_gadget.c:210 kref_put include/linux/kref.h:65 [inline] raw_release+0x219/0x290 drivers/usb/gadget/legacy/raw_gadget.c:424 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad5/0x29b0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888079dfa800 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 5 bytes inside of 32-byte region [ffff888079dfa800, ffff888079dfa820) The buggy address belongs to the physical page: page:ffffea0001e77e80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79dfa flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001c32340 dead000000000003 ffff888011841500 raw: 0000000000000000 0000000000400040 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 3657, tgid 3657 (syz-executor.1), ts 447360285948, free_ts 447356346917 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x7f1/0xe10 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] __kmalloc+0x32b/0x340 mm/slub.c:4425 kmalloc include/linux/slab.h:605 [inline] kzalloc include/linux/slab.h:733 [inline] tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline] tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 tomoyo_path_unlink+0x8e/0xd0 security/tomoyo/tomoyo.c:149 security_path_unlink+0xd7/0x150 security/security.c:1173 do_unlinkat+0x363/0x650 fs/namei.c:4293 __do_sys_unlink fs/namei.c:4345 [inline] __se_sys_unlink fs/namei.c:4343 [inline] __x64_sys_unlink+0xc6/0x110 fs/namei.c:4343 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] kmem_cache_alloc_node+0x2b1/0x3f0 mm/slub.c:3298 __alloc_skb+0x210/0x2f0 net/core/skbuff.c:422 alloc_skb_fclone include/linux/skbuff.h:1307 [inline] tcp_stream_alloc_skb+0x38/0x580 net/ipv4/tcp.c:861 tcp_sendmsg_locked+0xc36/0x2f80 net/ipv4/tcp.c:1325 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1483 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 sock_write_iter+0x291/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:584 ksys_write+0x1e8/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff888079dfa700: 00 00 00 00 fc fc fc fc 00 00 04 fc fc fc fc fc ffff888079dfa780: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc >ffff888079dfa800: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ^ ffff888079dfa880: 00 00 00 00 fc fc fc fc 00 00 04 fc fc fc fc fc ffff888079dfa900: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================