================================================================== BUG: KASAN: use-after-free in strcmp+0x9b/0xb0 lib/string.c:346 Read of size 1 at addr ffff888022f65184 by task syz-executor301/3589 CPU: 0 PID: 3589 Comm: syz-executor301 Not tainted 5.17.0-rc3-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+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 strcmp+0x9b/0xb0 lib/string.c:346 replace_vma_anon_name mm/madvise.c:141 [inline] madvise_update_vma+0x4e6/0x7f0 mm/madvise.c:212 madvise_vma_behavior+0x116/0x1910 mm/madvise.c:1043 madvise_walk_vmas+0x1d5/0x2d0 mm/madvise.c:1207 do_madvise mm/madvise.c:1385 [inline] do_madvise+0x249/0x3c0 mm/madvise.c:1343 __do_sys_madvise mm/madvise.c:1398 [inline] __se_sys_madvise mm/madvise.c:1396 [inline] __x64_sys_madvise+0xa6/0x110 mm/madvise.c:1396 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: 0033:0x7fbfbc791ff9 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe49c648d8 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbfbc791ff9 RDX: 000000000000000b RSI: 0000000000001000 RDI: 0000000020ffc000 RBP: 00007fbfbc755fe0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00007fbfbc756070 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3589: 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:586 [inline] anon_vma_name_alloc mm/madvise.c:75 [inline] replace_vma_anon_name mm/madvise.c:146 [inline] madvise_update_vma+0x546/0x7f0 mm/madvise.c:212 madvise_vma_anon_name+0x7c/0xc0 mm/madvise.c:1236 madvise_walk_vmas+0x1d5/0x2d0 mm/madvise.c:1207 madvise_set_anon_name+0xac/0xe0 mm/madvise.c:1269 prctl_set_vma kernel/sys.c:2305 [inline] __do_sys_prctl+0xeb5/0x12d0 kernel/sys.c:2594 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 3589: 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+0x130/0x160 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [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+0xcb/0x280 mm/slub.c:4562 vma_anon_name_free mm/madvise.c:88 [inline] kref_put include/linux/kref.h:65 [inline] free_vma_anon_name mm/madvise.c:125 [inline] free_vma_anon_name+0xeb/0x110 mm/madvise.c:116 vm_area_free+0x11/0x30 kernel/fork.c:376 __vma_adjust+0x836/0x24a0 mm/mmap.c:962 vma_merge+0x860/0xeb0 mm/mmap.c:1217 madvise_update_vma+0x1b6/0x7f0 mm/madvise.c:180 madvise_vma_behavior+0x116/0x1910 mm/madvise.c:1043 madvise_walk_vmas+0x1d5/0x2d0 mm/madvise.c:1207 do_madvise mm/madvise.c:1385 [inline] do_madvise+0x249/0x3c0 mm/madvise.c:1343 __do_sys_madvise mm/madvise.c:1398 [inline] __se_sys_madvise mm/madvise.c:1396 [inline] __x64_sys_madvise+0xa6/0x110 mm/madvise.c:1396 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 The buggy address belongs to the object at ffff888022f65180 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 4 bytes inside of 32-byte region [ffff888022f65180, ffff888022f651a0) The buggy address belongs to the page: page:ffffea00008bd940 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22f65 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00008be280 dead000000000003 ffff888010c41500 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 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 2964, ts 17156172357, free_ts 15612795258 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab mm/slub.c:1944 [inline] new_slab+0x28a/0x3b0 mm/slub.c:2004 ___slab_alloc+0x87c/0xe90 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] kzalloc include/linux/slab.h:715 [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+0x186/0x620 security/tomoyo/realpath.c:288 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:1337 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:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 kasan_depopulate_vmalloc_pte+0x5c/0x70 mm/kasan/shadow.c:380 apply_to_pte_range mm/memory.c:2541 [inline] apply_to_pmd_range mm/memory.c:2585 [inline] apply_to_pud_range mm/memory.c:2621 [inline] apply_to_p4d_range mm/memory.c:2657 [inline] __apply_to_page_range+0x686/0x1030 mm/memory.c:2691 kasan_release_vmalloc+0xa7/0xc0 mm/kasan/shadow.c:490 __purge_vmap_area_lazy+0x8f9/0x1c50 mm/vmalloc.c:1710 _vm_unmap_aliases.part.0+0x3f0/0x500 mm/vmalloc.c:2113 _vm_unmap_aliases mm/vmalloc.c:2087 [inline] vm_unmap_aliases+0x45/0x50 mm/vmalloc.c:2136 change_page_attr_set_clr+0x241/0x500 arch/x86/mm/pat/set_memory.c:1743 change_page_attr_set arch/x86/mm/pat/set_memory.c:1793 [inline] set_memory_nx+0xb2/0x110 arch/x86/mm/pat/set_memory.c:1941 free_init_pages+0x73/0xc0 arch/x86/mm/init.c:899 kernel_init+0x2e/0x1d0 init/main.c:1511 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff888022f65080: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff888022f65100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc >ffff888022f65180: fa fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff888022f65200: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff888022f65280: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================