out_of_memory+0x97d/0xb80 mm/oom_kill.c:1185 ================================================================== BUG: KCSAN: data-race in _prb_read_valid / prb_reserve write to 0xffffffff86d2e630 of 88 bytes by interrupt on cpu 0: prb_reserve+0x6e6/0xae0 kernel/printk/printk_ringbuffer.c:1690 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 print_daily_error_info+0x2d3/0x300 fs/ext4/super.c:3677 call_timer_fn+0x3b/0x2a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x426/0x620 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0x31/0x70 kernel/time/timer.c:2404 handle_softirqs+0xb9/0x2a0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x39/0xc0 kernel/softirq.c:723 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x74/0x80 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline] console_flush_all+0x540/0x6c0 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xa1/0x280 kernel/printk/printk.c:3413 vprintk_emit+0x3e4/0x600 kernel/printk/printk.c:2479 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 __ext4_grp_locked_error+0x56d/0x7d0 fs/ext4/super.c:1061 ext4_mb_generate_buddy+0x3a0/0x430 fs/ext4/mballoc.c:1312 ext4_mb_init_cache+0x898/0xc10 fs/ext4/mballoc.c:1497 ext4_mb_init_group+0x3d6/0x580 fs/ext4/mballoc.c:1636 ext4_mb_load_buddy_gfp+0x8d0/0x930 fs/ext4/mballoc.c:1703 ext4_mb_clear_bb fs/ext4/mballoc.c:6588 [inline] ext4_free_blocks+0x772/0x14a0 fs/ext4/mballoc.c:6790 ext4_free_branches+0x2fd/0x410 fs/ext4/indirect.c:1083 ext4_free_branches+0x1ea/0x410 fs/ext4/indirect.c:1042 ext4_free_branches+0x1ea/0x410 fs/ext4/indirect.c:1042 ext4_ind_truncate+0x7f1/0x840 fs/ext4/indirect.c:1208 ext4_truncate+0x6de/0xb00 fs/ext4/inode.c:4566 ext4_process_orphan+0x110/0x1c0 fs/ext4/orphan.c:337 ext4_orphan_cleanup+0x6a8/0xa00 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5670 [inline] ext4_fill_super+0x3408/0x37c0 fs/ext4/super.c:5793 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694 get_tree_bdev+0x1f/0x30 fs/super.c:1717 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5825 vfs_get_tree+0x57/0x1d0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x288/0x8d0 fs/namespace.c:3836 path_mount+0x4d0/0xbc0 fs/namespace.c:4146 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4325 __x64_sys_mount+0x67/0x80 fs/namespace.c:4325 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff86d2e630 of 8 bytes by task 19394 on cpu 1: desc_read kernel/printk/printk_ringbuffer.c:500 [inline] prb_first_seq kernel/printk/printk_ringbuffer.c:2014 [inline] _prb_read_valid+0x383/0x950 kernel/printk/printk_ringbuffer.c:2171 desc_update_last_finalized+0x8f/0x170 kernel/printk/printk_ringbuffer.c:1570 prb_final_commit+0x10d/0x150 kernel/printk/printk_ringbuffer.c:1839 vprintk_store+0x88b/0x910 kernel/printk/printk.c:2381 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 printk_stack_address arch/x86/kernel/dumpstack.c:70 [inline] __show_trace_log_lvl+0x460/0x560 arch/x86/kernel/dumpstack.c:282 __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x95/0xd0 lib/dump_stack.c:120 dump_stack+0x15/0x1b lib/dump_stack.c:129 dump_header+0x80/0x240 mm/oom_kill.c:467 oom_kill_process+0x295/0x350 mm/oom_kill.c:1047 out_of_memory+0x97d/0xb80 mm/oom_kill.c:1185 mem_cgroup_out_of_memory mm/memcontrol.c:1695 [inline] mem_cgroup_oom mm/memcontrol.c:1718 [inline] try_charge_memcg+0x62e/0xa10 mm/memcontrol.c:2456 try_charge mm/memcontrol.c:2556 [inline] charge_memcg mm/memcontrol.c:4745 [inline] mem_cgroup_swapin_charge_folio+0x103/0x1f0 mm/memcontrol.c:4831 __swap_cache_prepare_and_add+0x386/0x530 mm/swap_state.c:517 swap_cache_alloc_folio+0xa2/0x120 mm/swap_state.c:575 swap_cluster_readahead+0x36b/0x3d0 mm/swap_state.c:768 shmem_swapin_cluster mm/shmem.c:1785 [inline] shmem_swapin_folio+0x951/0x1360 mm/shmem.c:2349 shmem_get_folio_gfp+0x278/0xd60 mm/shmem.c:2500 shmem_get_folio mm/shmem.c:2673 [inline] shmem_write_begin+0xfc/0x1f0 mm/shmem.c:3327 generic_perform_write+0x183/0x490 mm/filemap.c:4314 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3502 lo_rw_aio+0x67d/0x730 drivers/block/loop.c:-1 do_req_filebacked drivers/block/loop.c:-1 [inline] loop_handle_cmd drivers/block/loop.c:1926 [inline] loop_process_work+0x56c/0xac0 drivers/block/loop.c:1961 loop_rootcg_workfn+0x22/0x30 drivers/block/loop.c:1992 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0x4de/0x9e0 kernel/workqueue.c:3358 worker_thread+0x581/0x770 kernel/workqueue.c:3439 kthread+0x22a/0x280 kernel/kthread.c:467 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x0000000000003af2 -> 0x0000000000005af2 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 19394 Comm: kworker/u8:5 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: loop2 loop_rootcg_workfn ================================================================== mem_cgroup_out_of_memory mm/memcontrol.c:1695 [inline] mem_cgroup_oom mm/memcontrol.c:1718 [inline] try_charge_memcg+0x62e/0xa10 mm/memcontrol.c:2456 try_charge mm/memcontrol.c:2556 [inline] charge_memcg mm/memcontrol.c:4745 [inline] mem_cgroup_swapin_charge_folio+0x103/0x1f0 mm/memcontrol.c:4831 __swap_cache_prepare_and_add+0x386/0x530 mm/swap_state.c:517 swap_cache_alloc_folio+0xa2/0x120 mm/swap_state.c:575 swap_cluster_readahead+0x36b/0x3d0 mm/swap_state.c:768 shmem_swapin_cluster mm/shmem.c:1785 [inline] shmem_swapin_folio+0x951/0x1360 mm/shmem.c:2349 shmem_get_folio_gfp+0x278/0xd60 mm/shmem.c:2500 shmem_get_folio mm/shmem.c:2673 [inline] shmem_write_begin+0xfc/0x1f0 mm/shmem.c:3327 generic_perform_write+0x183/0x490 mm/filemap.c:4314 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3502 lo_rw_aio+0x67d/0x730 drivers/block/loop.c:-1 do_req_filebacked drivers/block/loop.c:-1 [inline] loop_handle_cmd drivers/block/loop.c:1926 [inline] loop_process_work+0x56c/0xac0 drivers/block/loop.c:1961 loop_rootcg_workfn+0x22/0x30 drivers/block/loop.c:1992 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0x4de/0x9e0 kernel/workqueue.c:3358 worker_thread+0x581/0x770 kernel/workqueue.c:3439 kthread+0x22a/0x280 kernel/kthread.c:467 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 memory: usage 275700kB, limit 307200kB, failcnt 2389 memory+swap: usage 272520kB, limit 9007199254740988kB, failcnt 0 kmem: usage 160080kB, limit 9007199254740988kB, failcnt 0 Memory cgroup stats for /syz2 : cache 540672 rss 106496 shmem 0 mapped_file 65536 dirty 4096 writeback 12288 workingset_refault_anon 7068 workingset_refault_file 13232 swap 364544 swapcached 4792320 pgpgin 641902 pgpgout 641699 pgfault 706260 pgmajfault 1539 inactive_anon 176128 active_anon 98304 inactive_file 28672 active_file 524288 unevictable 0 hierarchical_memory_limit 314572800 hierarchical_memsw_limit 9223372036854771712 total_cache 540672 total_rss 106496 total_shmem 0 total_mapped_file 65536 total_dirty 4096 total_writeback 12288 total_workingset_refault_anon 7068 total_workingset_refault_file 13232 total_swap 364544 total_swapcached 4792320 total_pgpgin 641904 total_pgpgout 641701 total_pgfault 706283 total_pgmajfault 1539 total_inactive_anon 176128 total_active_anon 98304 total_inactive_file 28672 total_active_file 524288 total_unevictable 0 oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=/,mems_allowed=0,oom_memcg=/syz2,task_memcg=/syz2,task=syz.2.12302,pid=14853,uid=0 Memory cgroup out of memory: Killed process 14853 (syz.2.12302) total-vm:100576kB, anon-rss:1328kB, file-rss:26640kB, shmem-rss:0kB, UID:0 pgtables:164kB oom_score_adj:1000