================================================================== 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 ffff888110bfbbc0 by task udevd/19428 CPU: 0 PID: 19428 Comm: udevd Not tainted 6.0.0-syzkaller-09039-ga6afa4199d3d #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:2795 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 seq_read_iter+0x4f5/0x1280 fs/seq_file.c:230 kernfs_fop_read_iter+0x542/0x7a0 fs/kernfs/file.c:275 call_read_iter include/linux/fs.h:2184 [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: 0033:0x7f4dcc7f38fe 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:00007ffe62aa3658 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000562f6980cb10 RCX: 00007f4dcc7f38fe RDX: 0000000000001000 RSI: 0000562f698108b0 RDI: 0000000000000008 RBP: 00007f4dcc8c0380 R08: 0000000000000008 R09: 00007f4dcc8c3a60 R10: 0000000000002000 R11: 0000000000000246 R12: 0000562f6980cb10 R13: 0000000000000d68 R14: 00007f4dcc8bf780 R15: 0000000000000d68 Allocated by task 21591: 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+0x81/0xa0 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/0x27c0 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 21591: 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+0x14a/0x1b0 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 mm/slub.c:1785 [inline] slab_free mm/slub.c:3539 [inline] kfree+0xca/0x5c0 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+0x27c/0xa90 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 get_signal+0x1c3/0x2610 kernel/signal.c:2634 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+0x156/0x200 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 ffff888110bfbbc0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff888110bfbbc0, ffff888110bfbbe0) The buggy address belongs to the physical page: page:ffffea000442fec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x110bfb flags: 0x200000000000200(slab|node=0|zone=2) raw: 0200000000000200 0000000000000000 dead000000000001 ffff888100041500 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 4310, tgid 4308 (syz-executor.5), ts 98907240527, free_ts 97708611210 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x11cc/0x2a20 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+0x2ea/0x320 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+0x181/0x600 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x205/0x550 security/tomoyo/file.c:723 security_file_ioctl+0x50/0xb0 security/security.c:1552 __do_sys_ioctl fs/ioctl.c:864 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0xb3/0x200 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 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+0x5d2/0xb80 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page_list+0x176/0x900 mm/page_alloc.c:3522 release_pages+0xb79/0x11b0 mm/swap.c:1012 tlb_batch_pages_flush+0xa8/0x1a0 mm/mmu_gather.c:58 tlb_flush_mmu_free mm/mmu_gather.c:255 [inline] tlb_flush_mmu mm/mmu_gather.c:262 [inline] tlb_finish_mmu+0x147/0x7e0 mm/mmu_gather.c:353 exit_mmap+0x1d2/0x490 mm/mmap.c:3118 __mmput kernel/fork.c:1187 [inline] mmput+0xcc/0x410 kernel/fork.c:1208 exit_mm kernel/exit.c:510 [inline] do_exit+0x9e2/0x2930 kernel/exit.c:782 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x2387/0x2610 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+0x156/0x200 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 Memory state around the buggy address: ffff888110bfba80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff888110bfbb00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff888110bfbb80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff888110bfbc00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff888110bfbc80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================