On 03/04/2024 09:55, David Hildenbrand wrote: > On 02.04.24 19:32, syzbot wrote: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: c0b832517f62 Add linux-next specific files for 20240402 >> git tree: linux-next >> console output: https://syzkaller.appspot.com/x/log.txt?x=155b7db1180000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=afcaf46d374cec8c >> dashboard link: https://syzkaller.appspot.com/bug?extid=c641706ad4e9688cccdf >> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) >> 2.40 >> >> Unfortunately, I don't have any reproducer for this issue yet. >> >> Downloadable assets: >> disk image: >> https://storage.googleapis.com/syzbot-assets/0d36ec76edc7/disk-c0b83251.raw.xz >> vmlinux: >> https://storage.googleapis.com/syzbot-assets/6f9bb4e37dd0/vmlinux-c0b83251.xz >> kernel image: >> https://storage.googleapis.com/syzbot-assets/2349287b14b7/bzImage-c0b83251.xz >> >> IMPORTANT: if you fix the issue, please add the following tag to the commit: >> Reported-by: syzbot+c641706ad4e9688cccdf@xxxxxxxxxxxxxxxxxxxxxxxxx >> >> ===================================== >> WARNING: bad unlock balance detected! >> 6.9.0-rc2-next-20240402-syzkaller #0 Not tainted >> ------------------------------------- >> syz-executor.4/9211 is trying to release lock (ptlock_ptr(ptdesc)) at: >> [<ffffffff81f01c0f>] spin_unlock include/linux/spinlock.h:391 [inline] >> [<ffffffff81f01c0f>] madvise_cold_or_pageout_pte_range+0x170f/0x3990 >> mm/madvise.c:480 >> but there are no more locks to release! >> >> other info that might help us debug this: >> 1 lock held by syz-executor.4/9211: >> #0: ffff888067e40b18 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock >> include/linux/mmap_lock.h:144 [inline] >> #0: ffff888067e40b18 (&mm->mmap_lock){++++}-{3:3}, at: >> do_madvise+0x481/0x44a0 mm/madvise.c:1429 >> >> stack backtrace: >> CPU: 0 PID: 9211 Comm: syz-executor.4 Not tainted >> 6.9.0-rc2-next-20240402-syzkaller #0 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google >> 03/27/2024 >> Call Trace: >> <TASK> >> __dump_stack lib/dump_stack.c:88 [inline] >> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 >> print_unlock_imbalance_bug+0x256/0x2c0 kernel/locking/lockdep.c:5194 >> __lock_release kernel/locking/lockdep.c:5431 [inline] >> lock_release+0x599/0x9f0 kernel/locking/lockdep.c:5774 >> __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline] >> _raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186 >> spin_unlock include/linux/spinlock.h:391 [inline] >> madvise_cold_or_pageout_pte_range+0x170f/0x3990 mm/madvise.c:480 >> walk_pmd_range mm/pagewalk.c:143 [inline] >> walk_pud_range mm/pagewalk.c:221 [inline] >> walk_p4d_range mm/pagewalk.c:256 [inline] >> walk_pgd_range+0xba1/0x1810 mm/pagewalk.c:293 >> __walk_page_range+0x132/0x720 mm/pagewalk.c:395 >> walk_page_range+0x58f/0x7c0 mm/pagewalk.c:521 >> madvise_cold_page_range mm/madvise.c:562 [inline] >> madvise_cold mm/madvise.c:584 [inline] >> madvise_vma_behavior mm/madvise.c:1028 [inline] >> madvise_walk_vmas mm/madvise.c:1256 [inline] >> do_madvise+0x1e7b/0x44a0 mm/madvise.c:1442 >> __do_sys_madvise mm/madvise.c:1457 [inline] >> __se_sys_madvise mm/madvise.c:1455 [inline] >> __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1455 >> do_syscall_64+0xfb/0x240 >> entry_SYSCALL_64_after_hwframe+0x72/0x7a >> RIP: 0033:0x7ff60947dda9 >> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 >> 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 >> RSP: 002b:00007ff60a1b50c8 EFLAGS: 00000246 ORIG_RAX: 000000000000001c >> RAX: ffffffffffffffda RBX: 00007ff6095abf80 RCX: 00007ff60947dda9 >> RDX: 0000000000000014 RSI: 0000000000600000 RDI: 0000000020000000 >> RBP: 00007ff6094ca47a R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 >> R13: 000000000000000b R14: 00007ff6095abf80 R15: 00007fffacd4bc68 >> </TASK> >> ------------[ cut here ]------------ >> pvqspinlock: lock 0xffff88802ed23120 has corrupted value 0x0! >> WARNING: CPU: 1 PID: 9211 at kernel/locking/qspinlock_paravirt.h:510 >> __pv_queued_spin_unlock_slowpath+0x241/0x2f0 >> kernel/locking/qspinlock_paravirt.h:508 >> Modules linked in: >> CPU: 1 PID: 9211 Comm: syz-executor.4 Not tainted >> 6.9.0-rc2-next-20240402-syzkaller #0 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google >> 03/27/2024 >> RIP: 0010:__pv_queued_spin_unlock_slowpath+0x241/0x2f0 >> kernel/locking/qspinlock_paravirt.h:508 >> Code: 65 47 6e f6 4c 89 f0 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 9f 00 00 00 41 >> 8b 16 48 c7 c7 c0 26 cb 8b 4c 89 f6 e8 90 f3 cb f5 90 <0f> 0b 90 90 eb 8d 44 >> 89 f1 80 e1 07 38 c1 0f 8c 26 ff ff ff 4c 89 >> RSP: 0018:ffffc9000e477238 EFLAGS: 00010246 >> RAX: 5e9807e53cfb4f00 RBX: dffffc0000000000 RCX: 0000000000040000 >> RDX: ffffc9000b3b8000 RSI: 000000000003ffff RDI: 0000000000040000 >> RBP: dffffc0000000000 R08: ffffffff81580192 R09: fffffbfff1c39b10 >> R10: dffffc0000000000 R11: fffffbfff1c39b10 R12: 1ffff11005da4626 >> R13: ffff88802ed23130 R14: ffff88802ed23120 R15: ffff88802ed23120 >> FS: 00007ff60a1b56c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 00007fea8ecdaab3 CR3: 000000005d0fe000 CR4: 00000000003506f0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> Call Trace: >> <TASK> >> __raw_callee_save___pv_queued_spin_unlock_slowpath+0x15/0x30 >> .slowpath+0x9/0x16 >> pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:589 [inline] >> queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline] >> do_raw_spin_unlock+0x13c/0x8b0 kernel/locking/spinlock_debug.c:142 >> __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] >> _raw_spin_unlock+0x1e/0x50 kernel/locking/spinlock.c:186 >> spin_unlock include/linux/spinlock.h:391 [inline] >> madvise_cold_or_pageout_pte_range+0x170f/0x3990 mm/madvise.c:480 >> walk_pmd_range mm/pagewalk.c:143 [inline] >> walk_pud_range mm/pagewalk.c:221 [inline] >> walk_p4d_range mm/pagewalk.c:256 [inline] >> walk_pgd_range+0xba1/0x1810 mm/pagewalk.c:293 >> __walk_page_range+0x132/0x720 mm/pagewalk.c:395 >> walk_page_range+0x58f/0x7c0 mm/pagewalk.c:521 >> madvise_cold_page_range mm/madvise.c:562 [inline] >> madvise_cold mm/madvise.c:584 [inline] >> madvise_vma_behavior mm/madvise.c:1028 [inline] >> madvise_walk_vmas mm/madvise.c:1256 [inline] >> do_madvise+0x1e7b/0x44a0 mm/madvise.c:1442 >> __do_sys_madvise mm/madvise.c:1457 [inline] >> __se_sys_madvise mm/madvise.c:1455 [inline] >> __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1455 >> do_syscall_64+0xfb/0x240 >> entry_SYSCALL_64_after_hwframe+0x72/0x7a >> RIP: 0033:0x7ff60947dda9 >> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 >> 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 >> RSP: 002b:00007ff60a1b50c8 EFLAGS: 00000246 ORIG_RAX: 000000000000001c >> RAX: ffffffffffffffda RBX: 00007ff6095abf80 RCX: 00007ff60947dda9 >> RDX: 0000000000000014 RSI: 0000000000600000 RDI: 0000000020000000 >> RBP: 00007ff6094ca47a R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 >> R13: 000000000000000b R14: 00007ff6095abf80 R15: 00007fffacd4bc68 >> </TASK> >> >> >> --- >> This report is generated by a bot. It may contain errors. >> See https://goo.gl/tpsmEJ for more information about syzbot. >> syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. >> >> syzbot will keep track of this issue. See: >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot. >> >> If the report is already addressed, let syzbot know by replying with: >> #syz fix: exact-commit-title >> >> If you want to overwrite report's subsystems, reply with: >> #syz set subsystems: new-subsystem >> (See the list of subsystem names on the web dashboard) >> >> If the report is a duplicate of another one, reply with: >> #syz dup: exact-subject-of-another-report >> >> If you want to undo deduplication, reply with: >> #syz undup >> > > I'd suspect: > > commit 38456b4a3c609b205d5fdc6ef5347824a83fd818 > Author: Ryan Roberts <ryan.roberts@xxxxxxx> > Date: Wed Mar 27 14:45:37 2024 +0000 > > mm: madvise: avoid split during MADV_PAGEOUT and MADV_COLD > > but I don't immediately see the issue. CCing Ryan. Yes I believe this is the same issue that Barry reported [1]. I have a fix that will be in my v6 of the swap-out series (hopefully today). I've already asked Andrew to remove my v5 series from mm-unstable. Sorry about this! [1] https://lore.kernel.org/linux-mm/cbef3584-d3a7-4843-899e-3c1bb5430984@xxxxxxx/
