bisecting fixing commit since 78e709522d2c012cb0daad2e668506637bffb7c2 building syzkaller on 5ae8508a2dd5f8e16a2b9830ae9a6f37d54ec8e7 testing commit 78e709522d2c012cb0daad2e668506637bffb7c2 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: a9ee8b045e5ead72fbe14b5ba3f27f4e7dade83d639c18306638c2a676910138 run #0: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #1: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #2: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #3: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #4: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #5: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #6: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #7: crashed: KASAN: slab-out-of-bounds Write in null_skcipher_crypt run #8: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #9: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #10: crashed: KASAN: slab-out-of-bounds Write in null_skcipher_crypt run #11: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #12: crashed: KASAN: slab-out-of-bounds Write in null_skcipher_crypt run #13: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #14: crashed: KASAN: slab-out-of-bounds Write in null_skcipher_crypt run #15: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #16: crashed: KASAN: slab-out-of-bounds Write in null_skcipher_crypt run #17: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #18: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #19: boot failed: KFENCE: use-after-free in kvm_fastop_exception testing current HEAD fa5878760579a9feaa1de3bb2396cd23beb439ca testing commit fa5878760579a9feaa1de3bb2396cd23beb439ca compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 3e5374012dc8e368fc0f51552f68355290dab33ae1254db7312157fb190d88aa run #0: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #1: crashed: KASAN: slab-out-of-bounds Write in null_skcipher_crypt run #2: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #3: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #4: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #5: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #6: crashed: KASAN: slab-out-of-bounds Write in null_skcipher_crypt run #7: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #8: crashed: KASAN: use-after-free Write in null_skcipher_crypt run #9: crashed: KASAN: use-after-free Write in null_skcipher_crypt revisions tested: 2, total time: 27m22.596316294s (build: 12m27.172935377s, test: 14m28.229925466s) the crash still happens on HEAD commit msg: Merge tag 'linux-kselftest-kunit-fixes-5.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest crash: KASAN: use-after-free Write in null_skcipher_crypt ================================================================== BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: use-after-free in null_skcipher_crypt+0x8f/0xf0 crypto/crypto_null.c:85 Write of size 4096 at addr ffff88807c720000 by task syz-executor.4/9063 CPU: 1 PID: 9063 Comm: syz-executor.4 Not tainted 5.15.0-rc5-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+0x57/0x7d lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 memcpy+0x39/0x60 mm/kasan/shadow.c:66 memcpy include/linux/fortify-string.h:191 [inline] null_skcipher_crypt+0x8f/0xf0 crypto/crypto_null.c:85 crypto_authenc_encrypt+0x38b/0x530 crypto/authenc.c:222 esp6_output_tail+0x6de/0x1b60 net/ipv6/esp6.c:659 esp6_output+0x45d/0x910 net/ipv6/esp6.c:735 xfrm_output_one net/xfrm/xfrm_output.c:552 [inline] xfrm_output_resume+0x4ea/0x6110 net/xfrm/xfrm_output.c:587 NF_HOOK_COND include/linux/netfilter.h:296 [inline] xfrm6_output+0xe3/0x410 net/ipv6/xfrm6_output.c:92 ip6_send_skb+0x8f/0x2f0 net/ipv6/ip6_output.c:1911 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline] rawv6_sendmsg+0x21d6/0x30c0 net/ipv6/raw.c:956 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:724 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2409 ___sys_sendmsg+0xd3/0x150 net/socket.c:2463 __sys_sendmsg+0xb2/0x140 net/socket.c:2492 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: 0033:0x4665f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8222dfc188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 0000000000a9fb1f R14: 00007f8222dfc300 R15: 0000000000022000 Allocated by task 2961: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa4/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:596 [inline] tomoyo_realpath_from_path+0xb0/0x6a0 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x1fb/0x350 security/tomoyo/file.c:822 security_inode_getattr+0xab/0x100 security/security.c:1333 vfs_getattr fs/stat.c:157 [inline] vfs_fstat+0x2b/0x80 fs/stat.c:182 __do_sys_newfstat+0x72/0xd0 fs/stat.c:422 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 2961: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1700 [inline] slab_free_freelist_hook+0x81/0x190 mm/slub.c:1725 slab_free mm/slub.c:3483 [inline] kfree+0xe4/0x530 mm/slub.c:4543 tomoyo_realpath_from_path+0x14b/0x6a0 security/tomoyo/realpath.c:291 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x1fb/0x350 security/tomoyo/file.c:822 security_inode_getattr+0xab/0x100 security/security.c:1333 vfs_getattr fs/stat.c:157 [inline] vfs_fstat+0x2b/0x80 fs/stat.c:182 __do_sys_newfstat+0x72/0xd0 fs/stat.c:422 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 ffff88807c720000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff88807c720000, ffff88807c721000) The buggy address belongs to the page: page:ffffea0001f1c800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c720 head:ffffea0001f1c800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff88800fc42140 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 56648731453, free_ts 56643615744 prep_new_page mm/page_alloc.c:2424 [inline] get_page_from_freelist+0xa6f/0x2f50 mm/page_alloc.c:4153 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5375 alloc_slab_page mm/slub.c:1763 [inline] allocate_slab mm/slub.c:1900 [inline] new_slab+0x319/0x490 mm/slub.c:1963 ___slab_alloc+0x923/0xfe0 mm/slub.c:2994 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3081 slab_alloc_node mm/slub.c:3172 [inline] slab_alloc mm/slub.c:3214 [inline] __kmalloc+0x305/0x320 mm/slub.c:4387 kmalloc include/linux/slab.h:596 [inline] tomoyo_realpath_from_path+0xb0/0x6a0 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x1fb/0x350 security/tomoyo/file.c:822 security_inode_getattr+0xab/0x100 security/security.c:1333 vfs_getattr fs/stat.c:157 [inline] vfs_statx+0xe8/0x2e0 fs/stat.c:225 vfs_fstatat fs/stat.c:243 [inline] vfs_lstat include/linux/fs.h:3356 [inline] __do_sys_newlstat+0x85/0xe0 fs/stat.c:398 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:1338 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3315 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3394 __unfreeze_partials+0x340/0x360 mm/slub.c:2495 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0x95/0xb0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3214 [inline] kmem_cache_alloc+0x209/0x390 mm/slub.c:3219 getname_flags.part.0+0x4a/0x440 fs/namei.c:138 do_sys_openat2+0xd2/0x400 fs/open.c:1194 do_sys_open fs/open.c:1216 [inline] __do_sys_open fs/open.c:1224 [inline] __se_sys_open fs/open.c:1220 [inline] __x64_sys_open+0xfd/0x1a0 fs/open.c:1220 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: ffff88807c71ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807c71ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807c720000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c720080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c720100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================