================================================================== 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 ffff88807a25f880 by task udevd/2972 CPU: 0 PID: 2972 Comm: udevd Not tainted 6.0.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 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: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: 0033:0x7f1b723a78fe 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:00007ffe8ad864c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00005607cea41360 RCX: 00007f1b723a78fe RDX: 0000000000001000 RSI: 00005607ceaa8140 RDI: 000000000000000c RBP: 00007f1b72474380 R08: 000000000000000c R09: 00007f1b72477a60 R10: 0000000000400000 R11: 0000000000000246 R12: 00005607cea41360 R13: 0000000000000d68 R14: 00007f1b72473780 R15: 0000000000000d68 Allocated by task 29147: 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 29146: 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:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kfree+0xe2/0x580 mm/slub.c:4562 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 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88807a25f880 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff88807a25f880, ffff88807a25f8a0) The buggy address belongs to the physical page: page:ffffea0001e897c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7a25f flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000001 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 7750, tgid 7735 (syz-executor.1), ts 309019606779, free_ts 308911519859 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+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] slab_alloc mm/slub.c:3251 [inline] kmem_cache_alloc_trace+0x323/0x3e0 mm/slub.c:3282 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] ref_tracker_alloc+0x14c/0x550 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:3974 [inline] netdev_hold include/linux/netdevice.h:4003 [inline] dst_init+0xe0/0x520 net/core/dst.c:52 dst_alloc+0x16b/0x1f0 net/core/dst.c:96 rt_dst_alloc+0x51/0x430 net/ipv4/route.c:1633 __mkroute_output net/ipv4/route.c:2592 [inline] ip_route_output_key_hash_rcu+0x895/0x2bc0 net/ipv4/route.c:2814 ip_route_output_key_hash+0x18b/0x300 net/ipv4/route.c:2643 __ip_route_output_key include/net/route.h:140 [inline] ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2873 udp_sendmsg+0x1963/0x2740 net/ipv4/udp.c:1224 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 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_list+0x16f/0xb90 mm/page_alloc.c:3522 release_pages+0xbd3/0x1400 mm/swap.c:1012 __pagevec_release+0x77/0x100 mm/swap.c:1032 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] truncate_inode_pages_range+0x318/0x1510 mm/truncate.c:373 truncate_bdev_range+0xb2/0x270 block/bdev.c:109 blk_ioctl_zeroout block/ioctl.c:183 [inline] blkdev_common_ioctl+0xf98/0x1a30 block/ioctl.c:485 blkdev_ioctl+0x2be/0x800 block/ioctl.c:608 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 Memory state around the buggy address: ffff88807a25f780: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88807a25f800: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88807a25f880: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88807a25f900: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ffff88807a25f980: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc ==================================================================