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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff866d00a8 of 8 bytes by task 26505 on cpu 0:
 prb_reserve+0x740/0xb60
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2301
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68
 _printk+0x7a/0xa0 kernel/printk/printk.c:2432
 __ext4_std_error+0x34f/0x370 fs/ext4/super.c:973
 ext4_mb_clear_bb fs/ext4/mballoc.c:6550 [inline]
 ext4_free_blocks+0x1382/0x14b0 fs/ext4/mballoc.c:6652
 ext4_remove_blocks fs/ext4/extents.c:2547 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2712 [inline]
 ext4_ext_remove_space+0x19df/0x2940 fs/ext4/extents.c:2961
 ext4_ext_truncate+0xc4/0x150 fs/ext4/extents.c:4466
 ext4_truncate+0x776/0xb10 fs/ext4/inode.c:4217
 ext4_process_orphan+0x113/0x1c0 fs/ext4/orphan.c:339
 ext4_orphan_cleanup+0x696/0x9e0 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5610 [inline]
 ext4_fill_super+0x36bb/0x3a10 fs/ext4/super.c:5733
 get_tree_bdev_flags+0x29f/0x310 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5765
 vfs_get_tree+0x56/0x1e0 fs/super.c:1814
 do_new_mount+0x227/0x690 fs/namespace.c:3507
 path_mount+0x49b/0xb30 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x27c/0x2d0 fs/namespace.c:4034
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4034
 x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff866d00a8 of 8 bytes by task 3006 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline]
 _prb_read_valid+0x3bb/0xba0 kernel/printk/printk_ringbuffer.c:2114
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 syslog_print+0x157/0x760 kernel/printk/printk.c:1614
 do_syslog+0x397/0x7e0 kernel/printk/printk.c:1766
 __do_sys_syslog kernel/printk/printk.c:1858 [inline]
 __se_sys_syslog kernel/printk/printk.c:1856 [inline]
 __x64_sys_syslog+0x43/0x50 kernel/printk/printk.c:1856
 x64_sys_call+0x29be/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:104
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000002ae1 -> 0x0000000000004ae1

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3006 Comm: klogd Not tainted 6.12.0-syzkaller-00971-g158f238aa69d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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