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 ffff8881135bacc0 by task udevd/1177 CPU: 0 PID: 1177 Comm: udevd Not tainted 6.1.0-rc3-syzkaller-00029-g430d57f53eb1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 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:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 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:2800 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:2185 [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: 0033:0x7f0d7672c8fe 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:00007ffd229a82c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000564bc2374d00 RCX: 00007f0d7672c8fe RDX: 0000000000001000 RSI: 0000564bc237f6f0 RDI: 000000000000000c RBP: 00007f0d767f9380 R08: 000000000000000c R09: 00007f0d767fca60 R10: 0000000000000063 R11: 0000000000000246 R12: 0000564bc2374d00 R13: 0000000000000d68 R14: 00007f0d767f8780 R15: 0000000000000d68 Allocated by task 28067: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] __kasan_kmalloc+0x7a/0x90 mm/kasan/common.c:380 kmalloc include/linux/slab.h:576 [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 28070: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2a/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x144/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0x95/0x400 mm/slub.c:3674 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+0x16b/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb35/0x29a0 kernel/exit.c:820 do_group_exit+0xd0/0x2a0 kernel/exit.c:950 __do_sys_exit_group kernel/exit.c:961 [inline] __se_sys_exit_group kernel/exit.c:959 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:959 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 ffff8881135bacc0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8881135bacc0, ffff8881135bace0) The buggy address belongs to the physical page: page:ffffea00044d6e80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1135ba flags: 0x200000000000200(slab|node=0|zone=2) raw: 0200000000000200 ffffea000423e9c0 dead000000000002 ffff888100041500 raw: 0000000000000000 0000000080400040 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 4103, tgid 4095 (syz-executor.4), ts 87497358452, free_ts 87409194658 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x128b/0x2c70 mm/page_alloc.c:4288 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5555 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x2e7/0x3b0 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc+0x44/0xc0 mm/slab_common.c:968 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:712 [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:1554 __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:1459 [inline] free_pcp_prepare+0x64a/0xbf0 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page_list+0x183/0x9f0 mm/page_alloc.c:3529 release_pages+0xaeb/0x1110 mm/swap.c:1055 tlb_batch_pages_flush+0xa8/0x1a0 mm/mmu_gather.c:59 tlb_flush_mmu_free mm/mmu_gather.c:256 [inline] tlb_flush_mmu mm/mmu_gather.c:263 [inline] tlb_finish_mmu+0x147/0x7e0 mm/mmu_gather.c:363 exit_mmap+0x1fe/0x7a0 mm/mmap.c:3101 __mmput kernel/fork.c:1185 [inline] mmput+0xd5/0x420 kernel/fork.c:1207 exit_mm kernel/exit.c:516 [inline] do_exit+0xa39/0x29a0 kernel/exit.c:807 do_group_exit+0xd0/0x2a0 kernel/exit.c:950 __do_sys_exit_group kernel/exit.c:961 [inline] __se_sys_exit_group kernel/exit.c:959 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:959 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: ffff8881135bab80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff8881135bac00: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff8881135bac80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff8881135bad00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff8881135bad80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================