Hello,
Syzkaller has triggered a kernel WARNING with the following stacktrace when fuzzing a 4.14 kernel.
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xb7/0x107 lib/dump_stack.c:53
panic+0x1c9/0x3ae kernel/panic.c:181
__warn+0x160/0x1a8 kernel/panic.c:543
report_bug+0x123/0x18b lib/bug.c:186
fixup_bug+0x3e/0x77 arch/x86/kernel/traps.c:177
do_error_trap+0xdd/0x1e6 arch/x86/kernel/traps.c:295
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:944
do_blockdev_direct_IO+0x1b08/0x1b95 fs/direct-io.c:1373
ext4_direct_IO_write fs/ext4/inode.c:3696 [inline]
ext4_direct_IO+0x8de/0xdad fs/ext4/inode.c:3826
generic_file_direct_write+0x223/0x36b mm/filemap.c:2927
__generic_file_write_iter+0x12f/0x2f8 mm/filemap.c:3106
ext4_file_write_iter+0x97d/0xade fs/ext4/file.c:264
call_write_iter include/linux/fs.h:1782 [inline]
do_iter_readv_writev+0x1e4/0x27c fs/read_write.c:678
do_iter_write+0x136/0x18f fs/read_write.c:957
vfs_iter_write+0x81/0x98 fs/read_write.c:970
iter_file_splice_write+0x4dc/0x7a6 fs/splice.c:749
do_splice_from fs/splice.c:851 [inline]
direct_splice_actor+0x11e/0x129 fs/splice.c:1018
splice_direct_to_actor+0x342/0x5b0 fs/splice.c:973
do_splice_direct+0x180/0x1ff fs/splice.c:1061
do_sendfile+0x3e6/0x61c fs/read_write.c:1438
SYSC_sendfile64 fs/read_write.c:1499 [inline]
SyS_sendfile64+0xe9/0x128 fs/read_write.c:1485
do_syscall_64+0x203/0x241 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x42/0xb7
Could the following patch be applied in order to v4.14.y(The patch is present in v4.19.y)?
5a9d929d6e13 ("iomap: report collisions between directio and buffered writes to userspace")
Tests run:
- Chrome OS tryjobs
- Syzkaller reproducer
Thanks,
- Zubin
