====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc7-syzkaller-00149-g9bffa1ad25b8 #0 Not tainted ------------------------------------------------------ syz-executor/5385 is trying to acquire lock: ffffe8ffffc37f50 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:899 [inline] ffffe8ffffc37f50 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:931 [inline] ffffe8ffffc37f50 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1456 [inline] ffffe8ffffc37f50 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xa3b/0x1c30 mm/zswap.c:1563 but task is already holding lock: ffffffff8ea36f00 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3926 [inline] ffffffff8ea36f00 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xd4/0x3c0 mm/page_alloc.c:3951 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __fs_reclaim_acquire mm/page_alloc.c:3853 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3867 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4070 [inline] slab_alloc_node mm/slub.c:4148 [inline] __kmalloc_cache_node_noprof+0x40/0x3a0 mm/slub.c:4337 kmalloc_node_noprof include/linux/slab.h:924 [inline] zswap_cpu_comp_prepare+0xdc/0x400 mm/zswap.c:828 cpuhp_invoke_callback+0x415/0x830 kernel/cpu.c:204 cpuhp_issue_call+0x46f/0x7e0 __cpuhp_state_add_instance_cpuslocked+0x1ed/0x500 kernel/cpu.c:2437 __cpuhp_state_add_instance+0x27/0x40 kernel/cpu.c:2458 cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline] zswap_pool_create+0x38c/0x680 mm/zswap.c:291 zswap_setup+0x32a/0x4b0 mm/zswap.c:1811 do_one_initcall+0x248/0x870 init/main.c:1266 do_initcall_level+0x157/0x210 init/main.c:1328 do_initcalls+0x3f/0x80 init/main.c:1344 kernel_init_freeable+0x435/0x5d0 init/main.c:1577 kernel_init+0x1d/0x2b0 init/main.c:1466 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 acomp_ctx_get_cpu_lock mm/zswap.c:899 [inline] zswap_compress mm/zswap.c:931 [inline] zswap_store_page mm/zswap.c:1456 [inline] zswap_store+0xa3b/0x1c30 mm/zswap.c:1563 swap_writepage+0x647/0xce0 mm/page_io.c:279 shmem_writepage+0x1248/0x1610 mm/shmem.c:1579 pageout mm/vmscan.c:696 [inline] shrink_folio_list+0x3b68/0x5ca0 mm/vmscan.c:1374 evict_folios+0x3c92/0x58c0 mm/vmscan.c:4600 try_to_shrink_lruvec+0x9a6/0xc70 mm/vmscan.c:4799 shrink_one+0x3b9/0x850 mm/vmscan.c:4844 shrink_many mm/vmscan.c:4907 [inline] lru_gen_shrink_node mm/vmscan.c:4985 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5966 shrink_zones mm/vmscan.c:6225 [inline] do_try_to_free_pages+0x78c/0x1cf0 mm/vmscan.c:6287 try_to_free_pages+0x47c/0x1050 mm/vmscan.c:6537 __perform_reclaim mm/page_alloc.c:3929 [inline] __alloc_pages_direct_reclaim+0x178/0x3c0 mm/page_alloc.c:3951 __alloc_pages_slowpath+0x764/0x1020 mm/page_alloc.c:4382 __alloc_pages_noprof+0x49b/0x710 mm/page_alloc.c:4766 alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269 folio_alloc_mpol_noprof mm/mempolicy.c:2288 [inline] vma_alloc_folio_noprof+0x12e/0x230 mm/mempolicy.c:2318 folio_prealloc+0x2e/0x170 wp_page_copy mm/memory.c:3367 [inline] do_wp_page+0x1253/0x49b0 mm/memory.c:3759 handle_pte_fault+0xfa5/0x5ed0 mm/memory.c:5817 __handle_mm_fault mm/memory.c:5944 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6112 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 __put_user_4+0x11/0x20 arch/x86/lib/putuser.S:86 schedule_tail+0x96/0xb0 kernel/sched/core.c:5304 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:143 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex); lock(fs_reclaim); lock(&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex); *** DEADLOCK *** 2 locks held by syz-executor/5385: #0: ffff888012394fe0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff888012394fe0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6149 [inline] #0: ffff888012394fe0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:6209 #1: ffffffff8ea36f00 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3926 [inline] #1: ffffffff8ea36f00 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xd4/0x3c0 mm/page_alloc.c:3951 stack backtrace: CPU: 0 UID: 0 PID: 5385 Comm: syz-executor Not tainted 6.13.0-rc7-syzkaller-00149-g9bffa1ad25b8 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 acomp_ctx_get_cpu_lock mm/zswap.c:899 [inline] zswap_compress mm/zswap.c:931 [inline] zswap_store_page mm/zswap.c:1456 [inline] zswap_store+0xa3b/0x1c30 mm/zswap.c:1563 swap_writepage+0x647/0xce0 mm/page_io.c:279 shmem_writepage+0x1248/0x1610 mm/shmem.c:1579 pageout mm/vmscan.c:696 [inline] shrink_folio_list+0x3b68/0x5ca0 mm/vmscan.c:1374 evict_folios+0x3c92/0x58c0 mm/vmscan.c:4600 try_to_shrink_lruvec+0x9a6/0xc70 mm/vmscan.c:4799 shrink_one+0x3b9/0x850 mm/vmscan.c:4844 shrink_many mm/vmscan.c:4907 [inline] lru_gen_shrink_node mm/vmscan.c:4985 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5966 shrink_zones mm/vmscan.c:6225 [inline] do_try_to_free_pages+0x78c/0x1cf0 mm/vmscan.c:6287 try_to_free_pages+0x47c/0x1050 mm/vmscan.c:6537 __perform_reclaim mm/page_alloc.c:3929 [inline] __alloc_pages_direct_reclaim+0x178/0x3c0 mm/page_alloc.c:3951 __alloc_pages_slowpath+0x764/0x1020 mm/page_alloc.c:4382 __alloc_pages_noprof+0x49b/0x710 mm/page_alloc.c:4766 alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269 folio_alloc_mpol_noprof mm/mempolicy.c:2288 [inline] vma_alloc_folio_noprof+0x12e/0x230 mm/mempolicy.c:2318 folio_prealloc+0x2e/0x170 wp_page_copy mm/memory.c:3367 [inline] do_wp_page+0x1253/0x49b0 mm/memory.c:3759 handle_pte_fault+0xfa5/0x5ed0 mm/memory.c:5817 __handle_mm_fault mm/memory.c:5944 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6112 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:__put_user_4+0x11/0x20 arch/x86/lib/putuser.S:88 Code: 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 RSP: 0018:ffffc9000d9e7f00 EFLAGS: 00050202 RAX: 0000000000000002 RBX: 0000000000000000 RCX: 000055558ca927d0 RDX: 0000000000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5fb220 RBP: ffff88801f4eaad0 R08: ffffffff90198477 R09: 1ffffffff203308e R10: dffffc0000000000 R11: fffffbfff203308f R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000002 R15: dffffc0000000000 schedule_tail+0x96/0xb0 kernel/sched/core.c:5304 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:143 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 syz.0.9 (5385) used greatest stack depth: 16240 bytes left ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 84 00 test %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 00 add %al,(%rax) 6: 66 90 xchg %ax,%ax 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: f3 0f 1e fa endbr64 1c: 48 89 cb mov %rcx,%rbx 1f: 48 c1 fb 3f sar $0x3f,%rbx 23: 48 09 d9 or %rbx,%rcx 26: 0f 01 cb stac * 29: 89 01 mov %eax,(%rcx) <-- trapping instruction 2b: 31 c9 xor %ecx,%ecx 2d: 0f 01 ca clac 30: c3 ret 31: cc int3 32: cc int3 33: cc int3 34: cc int3 35: 0f 1f 00 nopl (%rax) 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop