bisecting fixing commit since 555161ee1b7a74e77ca70fd14ed8a5137c8108ac building syzkaller on 2e29b534005e52c57d726201644ea28ba33a9a3d testing commit 555161ee1b7a74e77ca70fd14ed8a5137c8108ac with gcc (GCC) 8.1.0 kernel signature: c4bd45cbf91b95d5df6121480600fa26fad6b1800c5ac753dbed03e35fde4403 run #0: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #1: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #2: crashed: general protection fault in scatterwalk_copychunks run #3: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #4: crashed: general protection fault in corrupted run #5: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #6: crashed: general protection fault in scatterwalk_copychunks run #7: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #8: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #9: crashed: KASAN: use-after-free Read in scatterwalk_copychunks testing current HEAD b09c34517e1ac4018e3bb75ed5c8610a8a1f486b testing commit b09c34517e1ac4018e3bb75ed5c8610a8a1f486b with gcc (GCC) 8.1.0 kernel signature: 4691eb429518d6c94bbc7234219ef1062e35fd1b60d622bef69d2c94cb2679ac run #0: crashed: general protection fault in scatterwalk_copychunks run #1: crashed: general protection fault in scatterwalk_copychunks run #2: crashed: general protection fault in scatterwalk_copychunks run #3: crashed: general protection fault in scatterwalk_copychunks run #4: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #5: crashed: general protection fault in scatterwalk_copychunks run #6: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #7: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks run #8: crashed: general protection fault in scatterwalk_copychunks run #9: crashed: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks revisions tested: 2, total time: 25m49.624868048s (build: 17m36.594635143s, test: 7m4.005978785s) the crash still happens on HEAD commit msg: Linux 4.19.149 crash: KASAN: slab-out-of-bounds Read in scatterwalk_copychunks R10: 0000000000000000 R11: 0000000000000246 R12: 00007f965f3ae6d4 R13: 00000000004c94f8 R14: 00000000004dfe58 R15: 0000000000000005 ================================================================== CPU: 0 PID: 7650 Comm: syz-executor.5 Not tainted 4.19.149-syzkaller #0 BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:373 [inline] BUG: KASAN: slab-out-of-bounds in memcpy_dir crypto/scatterwalk.c:28 [inline] BUG: KASAN: slab-out-of-bounds in scatterwalk_copychunks+0x1e1/0x610 crypto/scatterwalk.c:43 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Read of size 4096 at addr ffff8880a149a000 by task syz-executor.3/7652 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x177 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0x5/0x13 lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1588 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] __do_kmalloc mm/slab.c:3725 [inline] __kmalloc+0x2dd/0x770 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] aead_request_alloc include/crypto/aead.h:425 [inline] tls_push_record+0xff/0x1600 net/tls/tls_sw.c:209 tls_sw_sendpage+0x458/0xc00 net/tls/tls_sw.c:585 inet_sendpage+0x122/0x600 net/ipv4/af_inet.c:815 kernel_sendpage+0x60/0xd0 net/socket.c:3378 sock_sendpage+0x6d/0xd0 net/socket.c:847 pipe_to_sendpage+0x212/0x430 fs/splice.c:452 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x2cb/0x720 fs/splice.c:627 splice_from_pipe+0xbb/0x120 fs/splice.c:662 generic_splice_sendpage+0x10/0x20 fs/splice.c:833 do_splice_from fs/splice.c:852 [inline] do_splice+0x4fd/0x12d0 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459aa9 Code: 7d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 4b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f07cd211c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f07cd211c90 RCX: 0000000000459aa9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000075c070 R08: 000000011d100000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f07cd2126d4 R13: 00000000004c94f8 R14: 00000000004dfe58 R15: 0000000000000005 CPU: 1 PID: 7652 Comm: syz-executor.3 Not tainted 4.19.149-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x177 lib/dump_stack.c:118 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 memcpy+0x23/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:373 [inline] memcpy_dir crypto/scatterwalk.c:28 [inline] scatterwalk_copychunks+0x1e1/0x610 crypto/scatterwalk.c:43 scatterwalk_map_and_copy+0x128/0x190 crypto/scatterwalk.c:72 gcmaes_encrypt.constprop.15+0x6d6/0xda0 arch/x86/crypto/aesni-intel_glue.c:956 generic_gcmaes_encrypt+0xfd/0x150 arch/x86/crypto/aesni-intel_glue.c:1297 crypto_aead_encrypt include/crypto/aead.h:335 [inline] gcmaes_wrapper_encrypt+0x109/0x180 arch/x86/crypto/aesni-intel_glue.c:1130 crypto_aead_encrypt include/crypto/aead.h:335 [inline] tls_do_encryption net/tls/tls_sw.c:193 [inline] tls_push_record+0x9ae/0x1600 net/tls/tls_sw.c:228 tls_sw_sendpage+0x458/0xc00 net/tls/tls_sw.c:585 inet_sendpage+0x122/0x600 net/ipv4/af_inet.c:815 kernel_sendpage+0x60/0xd0 net/socket.c:3378 sock_sendpage+0x6d/0xd0 net/socket.c:847 pipe_to_sendpage+0x212/0x430 fs/splice.c:452 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x2cb/0x720 fs/splice.c:627 splice_from_pipe+0xbb/0x120 fs/splice.c:662 generic_splice_sendpage+0x10/0x20 fs/splice.c:833 do_splice_from fs/splice.c:852 [inline] do_splice+0x4fd/0x12d0 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459aa9 Code: 7d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 4b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6589426c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f6589426c90 RCX: 0000000000459aa9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 000000011d100000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f65894276d4 R13: 00000000004c94f8 R14: 00000000004dfe58 R15: 0000000000000005 Allocated by task 3621: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3559 getname_flags+0xb8/0x520 fs/namei.c:140 user_path_at_empty+0x1e/0x40 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0xbe/0x150 fs/stat.c:185 vfs_lstat include/linux/fs.h:3138 [inline] __do_sys_newlstat+0x85/0xe0 fs/stat.c:350 __se_sys_newlstat fs/stat.c:344 [inline] __x64_sys_newlstat+0x4f/0x70 fs/stat.c:344 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 3621: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3765 putname+0xa8/0xe0 fs/namei.c:261 filename_lookup.part.57+0x1ec/0x360 fs/namei.c:2358 filename_lookup fs/namei.c:2342 [inline] user_path_at_empty+0x39/0x40 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0xbe/0x150 fs/stat.c:185 vfs_lstat include/linux/fs.h:3138 [inline] __do_sys_newlstat+0x85/0xe0 fs/stat.c:350 __se_sys_newlstat fs/stat.c:344 [inline] __x64_sys_newlstat+0x4f/0x70 fs/stat.c:344 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a149ae80 which belongs to the cache names_cache of size 4096 The buggy address is located 3712 bytes to the left of 4096-byte region [ffff8880a149ae80, ffff8880a149be80) The buggy address belongs to the page: page:ffffea0002852680 count:1 mapcount:0 mapping:ffff88821bc47800 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000008100(slab|head) raw: 01fffc0000008100 ffffea0002219208 ffffea0002239408 ffff88821bc47800 raw: 0000000000000000 ffff8880a149ae80 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a1499f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a1499f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a149a000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a149a080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a149a100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================