================================================================== BUG: KCSAN: data-race in shmem_add_to_page_cache / shmem_recalc_inode write to 0xffff8880a15c6af8 of 8 bytes by task 10247 on cpu 0: shmem_add_to_page_cache+0x4b0/0x6c0 mm/shmem.c:643 shmem_getpage_gfp+0x43f/0x16c0 mm/shmem.c:1871 shmem_fault+0x117/0x4b0 mm/shmem.c:2062 __do_fault+0xa8/0x1e0 mm/memory.c:3450 do_read_fault mm/memory.c:3846 [inline] do_fault mm/memory.c:3975 [inline] handle_pte_fault mm/memory.c:4215 [inline] __handle_mm_fault+0x295c/0x2da0 mm/memory.c:4345 handle_mm_fault+0x21c/0x540 mm/memory.c:4382 faultin_page mm/gup.c:879 [inline] __get_user_pages+0x533/0x11c0 mm/gup.c:1098 populate_vma_page_range+0xdc/0x100 mm/gup.c:1430 __mm_populate+0x168/0x2b0 mm/gup.c:1478 mm_populate include/linux/mm.h:2562 [inline] vm_mmap_pgoff+0x185/0x190 mm/util.c:511 ksys_mmap_pgoff+0x96/0x420 mm/mmap.c:1595 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880a15c6af8 of 8 bytes by task 10250 on cpu 1: shmem_recalc_inode+0x50/0x180 mm/shmem.c:306 shmem_getpage_gfp+0x5ca/0x16c0 mm/shmem.c:1885 shmem_fault+0x117/0x4b0 mm/shmem.c:2062 __do_fault+0xa8/0x1e0 mm/memory.c:3450 do_shared_fault mm/memory.c:3901 [inline] do_fault mm/memory.c:3979 [inline] handle_pte_fault mm/memory.c:4215 [inline] __handle_mm_fault+0x27bc/0x2da0 mm/memory.c:4345 handle_mm_fault+0x21c/0x540 mm/memory.c:4382 do_user_addr_fault arch/x86/mm/fault.c:1464 [inline] do_page_fault+0x48a/0xa96 arch/x86/mm/fault.c:1535 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203 copy_user_enhanced_fast_string+0xe/0x30 arch/x86/lib/copy_user_64.S:204 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:74 [inline] _copy_to_user+0x8f/0xb0 lib/usercopy.c:30 copy_to_user include/linux/uaccess.h:152 [inline] extract_crng_user drivers/char/random.c:1084 [inline] urandom_read_nowarn.isra.0+0xa2/0x370 drivers/char/random.c:1835 __do_sys_getrandom drivers/char/random.c:2032 [inline] __se_sys_getrandom drivers/char/random.c:2007 [inline] __x64_sys_getrandom+0xdb/0x150 drivers/char/random.c:2007 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 10250 Comm: syz-executor.5 Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================