syzbot

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BUG: KCSAN: data-race in inode_update_timestamps / inode_update_timestamps

write to 0xffff8881078fd878 of 8 bytes by task 9081 on cpu 1:
 inode_set_ctime_to_ts include/linux/fs.h:1617 [inline]
 inode_set_ctime_current fs/inode.c:2515 [inline]
 inode_update_timestamps+0xb5/0x280 fs/inode.c:1861
 generic_update_time fs/inode.c:1900 [inline]
 inode_update_time fs/inode.c:1920 [inline]
 __file_update_time fs/inode.c:2109 [inline]
 file_update_time+0x22f/0x2c0 fs/inode.c:2139
 ext4_page_mkwrite+0x1a4/0xb70 fs/ext4/inode.c:6053
 do_page_mkwrite mm/memory.c:3093 [inline]
 wp_page_shared mm/memory.c:3495 [inline]
 do_wp_page+0xc69/0x22b0 mm/memory.c:3645
 handle_pte_fault mm/memory.c:5396 [inline]
 __handle_mm_fault mm/memory.c:5523 [inline]
 handle_mm_fault+0xb9b/0x2a80 mm/memory.c:5688
 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x296/0x650 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
 rep_stos_alternative+0x40/0x80 arch/x86/lib/clear_page_64.S:92
 __clear_user arch/x86/include/asm/uaccess_64.h:172 [inline]
 clear_user arch/x86/include/asm/uaccess_64.h:189 [inline]
 zero_to_user_iter lib/iov_iter.c:442 [inline]
 iterate_ubuf include/linux/iov_iter.h:29 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
 iterate_and_advance include/linux/iov_iter.h:271 [inline]
 iov_iter_zero+0xf6/0xa30 lib/iov_iter.c:455
 read_iter_zero+0x5e/0x1e0 drivers/char/mem.c:480
 new_sync_read fs/read_write.c:395 [inline]
 vfs_read+0x5e6/0x6e0 fs/read_write.c:476
 ksys_read+0xeb/0x1b0 fs/read_write.c:619
 __do_sys_read fs/read_write.c:629 [inline]
 __se_sys_read fs/read_write.c:627 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:627
 x64_sys_call+0x27e5/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:1
 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 0xffff8881078fd878 of 8 bytes by task 9063 on cpu 0:
 inode_get_ctime include/linux/fs.h:1611 [inline]
 inode_update_timestamps+0x59/0x280 fs/inode.c:1858
 generic_update_time fs/inode.c:1900 [inline]
 inode_update_time fs/inode.c:1920 [inline]
 __file_update_time fs/inode.c:2109 [inline]
 file_update_time+0x22f/0x2c0 fs/inode.c:2139
 ext4_page_mkwrite+0x1a4/0xb70 fs/ext4/inode.c:6053
 do_page_mkwrite mm/memory.c:3093 [inline]
 wp_page_shared mm/memory.c:3495 [inline]
 do_wp_page+0xc69/0x22b0 mm/memory.c:3645
 handle_pte_fault mm/memory.c:5396 [inline]
 __handle_mm_fault mm/memory.c:5523 [inline]
 handle_mm_fault+0xb9b/0x2a80 mm/memory.c:5688
 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x296/0x650 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
 __put_user_nocheck_4+0x7/0x20 arch/x86/lib/putuser.S:95
 ____sys_recvmsg+0x1a3/0x280 net/socket.c:2817
 ___sys_recvmsg net/socket.c:2846 [inline]
 do_recvmmsg+0x2eb/0x720 net/socket.c:2940
 __sys_recvmmsg net/socket.c:3019 [inline]
 __do_sys_recvmmsg net/socket.c:3042 [inline]
 __se_sys_recvmmsg net/socket.c:3035 [inline]
 __x64_sys_recvmmsg+0xe2/0x170 net/socket.c:3035
 x64_sys_call+0x271d/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:300
 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: 0x0000000013650412 -> 0x0000000013fd9a92

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9063 Comm: syz.4.1082 Not tainted 6.10.0-rc5-syzkaller-00018-g55027e689933 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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