================================================================== BUG: KASAN: use-after-free in dev_uevent+0x712/0x780 drivers/base/core.c:2320 Read of size 8 at addr ffff888072106098 by task udevd/3596 CPU: 1 PID: 3596 Comm: udevd Not tainted 5.17.0-rc2-next-20220204-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xa5/0x3e0 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 dev_uevent+0x712/0x780 drivers/base/core.c:2320 uevent_show+0x1b8/0x380 drivers/base/core.c:2391 dev_attr_show+0x4b/0x90 drivers/base/core.c:2094 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+0x44f/0x5f0 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2069 [inline] new_sync_read+0x429/0x6e0 fs/read_write.c:401 vfs_read+0x35c/0x600 fs/read_write.c:482 ksys_read+0x12d/0x250 fs/read_write.c:620 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+0x44/0xae RIP: 0033:0x7f824f4e08fe 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:00007ffd21f4c908 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f82505b4cf0 RCX: 00007f824f4e08fe RDX: 0000000000001000 RSI: 00007f8250597820 RDI: 0000000000000008 RBP: 00007f824f5ad380 R08: 0000000000000008 R09: 00007f824f5b0a60 R10: 0000000000000010 R11: 0000000000000246 R12: 00007f82505b4cf0 R13: 0000000000000d68 R14: 00007f824f5ac780 R15: 0000000000000d68 Allocated by task 8349: 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:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:715 [inline] dev_new drivers/usb/gadget/legacy/raw_gadget.c:183 [inline] raw_open+0x8d/0x4c0 drivers/usb/gadget/legacy/raw_gadget.c:373 misc_open+0x372/0x4a0 drivers/char/misc.c:141 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b9/0x1240 fs/open.c:957 do_open fs/namei.c:3476 [inline] path_openat+0x1c9e/0x2940 fs/namei.c:3609 do_filp_open+0x1aa/0x400 fs/namei.c:3636 do_sys_openat2+0x16d/0x4d0 fs/open.c:1347 do_sys_open fs/open.c:1363 [inline] __do_sys_openat fs/open.c:1379 [inline] __se_sys_openat fs/open.c:1374 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1374 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+0x44/0xae Freed by task 8348: 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:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:226 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kfree+0xce/0x2d0 mm/slub.c:4562 kref_put include/linux/kref.h:65 [inline] raw_release+0x218/0x290 drivers/usb/gadget/legacy/raw_gadget.c:412 __fput+0x286/0x9f0 fs/file_table.c:311 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888072106000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 152 bytes inside of 4096-byte region [ffff888072106000, ffff888072107000) The buggy address belongs to the page: page:ffffea0001c84000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x72100 head:ffffea0001c84000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea000062ce00 dead000000000002 ffff888010c42140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 2964, ts 338153501828, free_ts 337696877006 prep_new_page mm/page_alloc.c:2489 [inline] get_page_from_freelist+0x13ea/0x31d0 mm/page_alloc.c:4219 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5435 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2268 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab mm/slub.c:1944 [inline] new_slab+0x295/0x400 mm/slub.c:2004 ___slab_alloc+0x7ed/0xe00 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] slab_alloc mm/slub.c:3238 [inline] __kmalloc+0x2fb/0x340 mm/slub.c:4420 kmalloc include/linux/slab.h:586 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1350 vfs_getattr fs/stat.c:157 [inline] vfs_statx+0x164/0x390 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat+0x96/0x120 fs/stat.c:412 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+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3376 [inline] free_unref_page+0x19/0x6c0 mm/page_alloc.c:3455 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2536 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3243 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags include/linux/audit.h:323 [inline] getname+0x8e/0xd0 fs/namei.c:217 do_sys_openat2+0xf5/0x4d0 fs/open.c:1341 do_sys_open fs/open.c:1363 [inline] __do_sys_openat fs/open.c:1379 [inline] __se_sys_openat fs/open.c:1374 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1374 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+0x44/0xae Memory state around the buggy address: ffff888072105f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888072106000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888072106080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888072106100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888072106180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================