syzbot

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BUG: KCSAN: data-race in exec_mmap / unmap_region

write to 0xffff8881049ce0b0 of 8 bytes by task 1479 on cpu 0:
 update_hiwater_rss include/linux/mm.h:2070 [inline]
 unmap_region+0x12b/0x1e0 mm/mmap.c:2653
 __do_munmap+0xd85/0x11b0 mm/mmap.c:2868
 __vm_munmap mm/mmap.c:2891 [inline]
 __do_sys_munmap+0x97/0x150 mm/mmap.c:2916
 __se_sys_munmap mm/mmap.c:2913 [inline]
 __x64_sys_munmap+0x2d/0x40 mm/mmap.c:2913
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881049ce0b0 of 8 bytes by task 25135 on cpu 1:
 get_mm_hiwater_rss include/linux/mm.h:2057 [inline]
 setmax_mm_hiwater_rss include/linux/mm.h:2087 [inline]
 exec_mmap+0x1e3/0x360 fs/exec.c:1032
 begin_new_exec+0x7a2/0x1060 fs/exec.c:1293
 load_elf_binary+0x62a/0x1970 fs/binfmt_elf.c:1002
 search_binary_handler fs/exec.c:1726 [inline]
 exec_binprm+0x1d9/0x800 fs/exec.c:1767
 bprm_execve+0x379/0x4e0 fs/exec.c:1836
 do_execveat_common+0x853/0x960 fs/exec.c:1941
 do_execve fs/exec.c:2011 [inline]
 __do_sys_execve fs/exec.c:2087 [inline]
 __se_sys_execve fs/exec.c:2082 [inline]
 __x64_sys_execve+0x56/0x70 fs/exec.c:2082
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000000002a1 -> 0x00000000000002a4

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25135 Comm: dhcpcd Tainted: G        W         5.18.0-rc3-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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