================================================================== 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 ffff888022f7bdc9 by task udevd/3759 CPU: 0 PID: 3759 Comm: udevd Not tainted 6.0.0-rc2-syzkaller-00054-gc40e8341e3b3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 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/0x6e9 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:607 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: 0033:0x7f0c213258fe 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:00007fff32ec41a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055d3d872b1c0 RCX: 00007f0c213258fe RDX: 0000000000001000 RSI: 000055d3d87a8770 RDI: 0000000000000008 RBP: 00007f0c213f2380 R08: 0000000000000008 R09: 00007f0c213f5a60 R10: 000055d3d87a9770 R11: 0000000000000246 R12: 000055d3d872b1c0 R13: 0000000000000d68 R14: 00007f0c213f1780 R15: 0000000000000d68 Allocated by task 5375: 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+0xa6/0xd0 mm/kasan/common.c:525 kasan_kmalloc include/linux/kasan.h:234 [inline] kmem_cache_alloc_trace+0x25a/0x460 mm/slab.c:3559 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 5400: 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+0x13d/0x1a0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3418 [inline] kfree+0x173/0x390 mm/slab.c:3786 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 get_signal+0x238c/0x2610 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:299 The buggy address belongs to the object at ffff888022f7bdc0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 9 bytes inside of 32-byte region [ffff888022f7bdc0, ffff888022f7bde0) The buggy address belongs to the physical page: page:ffffea00008bdec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888022f7bfc1 pfn:0x22f7b flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001dd1dc8 ffffea00012fa208 ffff888011840100 raw: ffff888022f7bfc1 ffff888022f7b000 0000000100000036 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 0x342220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 4822, tgid 4818 (syz-executor.2), ts 108711123854, free_ts 108668858870 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:5515 __alloc_pages_node include/linux/gfp.h:243 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2569 cache_alloc_refill+0x27f/0x380 mm/slab.c:2942 ____cache_alloc mm/slab.c:3018 [inline] ____cache_alloc mm/slab.c:3001 [inline] __do_cache_alloc mm/slab.c:3246 [inline] slab_alloc mm/slab.c:3287 [inline] kmem_cache_alloc_trace+0x362/0x460 mm/slab.c:3557 kmalloc include/linux/slab.h:600 [inline] dccp_ackvec_parsed_add+0x54/0x250 net/dccp/ackvec.c:354 ccid2_hc_tx_parse_options+0x8a/0xa0 net/dccp/ccids/ccid2.c:505 ccid_hc_tx_parse_options net/dccp/ccid.h:204 [inline] dccp_parse_options+0x56c/0x13c0 net/dccp/options.c:230 dccp_rcv_established+0x43/0x160 net/dccp/input.c:370 dccp_v6_do_rcv+0xa13/0xc60 net/dccp/ipv6.c:621 sk_backlog_rcv include/net/sock.h:1100 [inline] __release_sock+0x12f/0x3a0 net/core/sock.c:2850 release_sock+0x54/0x1b0 net/core/sock.c:3406 dccp_sendmsg+0x697/0xca0 net/dccp/proto.c:785 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 ____sys_sendmsg+0x334/0x810 net/socket.c:2482 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 slab_destroy mm/slab.c:1615 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1635 cache_flusharray mm/slab.c:3389 [inline] ___cache_free+0x2a8/0x3d0 mm/slab.c:3452 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x97/0xb0 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 mm/slab.c:3294 [inline] __kmem_cache_alloc_lru mm/slab.c:3471 [inline] kmem_cache_alloc+0x214/0x520 mm/slab.c:3491 prepare_creds+0x3f/0x7b0 kernel/cred.c:260 access_override_creds fs/open.c:376 [inline] do_faccessat+0x3f4/0x850 fs/open.c:440 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 Memory state around the buggy address: ffff888022f7bc80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff888022f7bd00: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff888022f7bd80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff888022f7be00: fa fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff888022f7be80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc 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