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KMSAN: uninit-value in __mpol_equal

Status: auto-closed as invalid on 2021/08/22 02:07
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+b1d978f749455b49537a@syzkaller.appspotmail.com
First crash: 1097d, last: 1097d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] KMSAN: uninit-value in __mpol_equal 0 (1) 2021/05/01 06:08
▶ ▼ Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in __mpol_equal (2) mm 5 942d 946d 0/26 closed as invalid on 2021/09/27 07:07
upstream KMSAN: uninit-value in __mpol_equal (3) mm 13 917d 941d 20/26 fixed on 2022/03/08 16:11

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in __mpol_equal+0x617/0x690 mm/mempolicy.c:2340
CPU: 0 PID: 20507 Comm: syz-executor.4 Not tainted 5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 __mpol_equal+0x617/0x690 mm/mempolicy.c:2340
 mpol_equal include/linux/mempolicy.h:108 [inline]
 vma_merge+0x47e/0x2210 mm/mmap.c:1187
 mbind_range mm/mempolicy.c:830 [inline]
 do_mbind+0x19c9/0x38c0 mm/mempolicy.c:1350
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 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:00007fd2ba516188 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9
RDX: 0000000000002001 RSI: 0000000000800000 RDI: 0000000020001000
RBP: 00000000004bfbb9 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 0000000000a9fb1f R14: 00007fd2ba516300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2922 [inline]
 slab_alloc mm/slub.c:2931 [inline]
 kmem_cache_alloc+0x895/0x1030 mm/slub.c:2936
 mpol_new mm/mempolicy.c:302 [inline]
 do_mbind+0x8d5/0x38c0 mm/mempolicy.c:1306
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
=====================================================
=====================================================
BUG: KMSAN: uninit-value in __mpol_equal+0x617/0x690 mm/mempolicy.c:2340
CPU: 0 PID: 20507 Comm: syz-executor.4 Tainted: G    B             5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 __mpol_equal+0x617/0x690 mm/mempolicy.c:2340
 mpol_equal include/linux/mempolicy.h:108 [inline]
 vma_merge+0x47e/0x2210 mm/mmap.c:1187
 mbind_range mm/mempolicy.c:830 [inline]
 do_mbind+0x19c9/0x38c0 mm/mempolicy.c:1350
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 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:00007fd2ba516188 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9
RDX: 0000000000002001 RSI: 0000000000800000 RDI: 0000000020001000
RBP: 00000000004bfbb9 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 0000000000a9fb1f R14: 00007fd2ba516300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2922 [inline]
 slab_alloc mm/slub.c:2931 [inline]
 kmem_cache_alloc+0x895/0x1030 mm/slub.c:2936
 mpol_new mm/mempolicy.c:302 [inline]
 do_mbind+0x8d5/0x38c0 mm/mempolicy.c:1306
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
=====================================================
=====================================================
BUG: KMSAN: uninit-value in __mpol_equal+0x617/0x690 mm/mempolicy.c:2340
CPU: 0 PID: 20507 Comm: syz-executor.4 Tainted: G    B             5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 __mpol_equal+0x617/0x690 mm/mempolicy.c:2340
 mpol_equal include/linux/mempolicy.h:108 [inline]
 vma_merge+0x47e/0x2210 mm/mmap.c:1187
 mbind_range mm/mempolicy.c:830 [inline]
 do_mbind+0x19c9/0x38c0 mm/mempolicy.c:1350
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 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:00007fd2ba516188 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9
RDX: 0000000000002001 RSI: 0000000000800000 RDI: 0000000020001000
RBP: 00000000004bfbb9 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 0000000000a9fb1f R14: 00007fd2ba516300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2922 [inline]
 slab_alloc mm/slub.c:2931 [inline]
 kmem_cache_alloc+0x895/0x1030 mm/slub.c:2936
 mpol_new mm/mempolicy.c:302 [inline]
 do_mbind+0x8d5/0x38c0 mm/mempolicy.c:1306
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
=====================================================
=====================================================
BUG: KMSAN: uninit-value in __mpol_equal mm/mempolicy.c:2340 [inline]
BUG: KMSAN: uninit-value in mpol_equal include/linux/mempolicy.h:108 [inline]
BUG: KMSAN: uninit-value in mbind_range mm/mempolicy.c:836 [inline]
BUG: KMSAN: uninit-value in do_mbind+0x2ee6/0x38c0 mm/mempolicy.c:1350
CPU: 0 PID: 20507 Comm: syz-executor.4 Tainted: G    B             5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 __mpol_equal mm/mempolicy.c:2340 [inline]
 mpol_equal include/linux/mempolicy.h:108 [inline]
 mbind_range mm/mempolicy.c:836 [inline]
 do_mbind+0x2ee6/0x38c0 mm/mempolicy.c:1350
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 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:00007fd2ba516188 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 00000000004665f9
RDX: 0000000000002001 RSI: 0000000000800000 RDI: 0000000020001000
RBP: 00000000004bfbb9 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 0000000000a9fb1f R14: 00007fd2ba516300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2922 [inline]
 slab_alloc mm/slub.c:2931 [inline]
 kmem_cache_alloc+0x895/0x1030 mm/slub.c:2936
 mpol_new mm/mempolicy.c:302 [inline]
 do_mbind+0x8d5/0x38c0 mm/mempolicy.c:1306
 kernel_mbind mm/mempolicy.c:1478 [inline]
 __do_sys_mbind mm/mempolicy.c:1485 [inline]
 __se_sys_mbind+0x3a6/0x3c0 mm/mempolicy.c:1481
 __x64_sys_mbind+0x6e/0x90 mm/mempolicy.c:1481
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
=====================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/04/24 02:07 https://github.com/google/kmsan.git master 4ebaab5fb428 17f0b706 .config console log report info ci-upstream-kmsan-gce KMSAN: uninit-value in __mpol_equal
* Struck through repros no longer work on HEAD.