On Wed, Sep 5, 2018 at 11:50 AM, Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote: > On Wed, Sep 5, 2018 at 2:25 PM Jan Kara <jack@xxxxxxx> wrote: >> >> On Wed 05-09-18 00:13:02, syzbot wrote: >> > Hello, >> > >> > syzbot found the following crash on: >> > >> > HEAD commit: 387ac6229ecf Add linux-next specific files for 20180905 >> > git tree: linux-next >> > console output: https://syzkaller.appspot.com/x/log.txt?x=149c67a6400000 >> > kernel config: https://syzkaller.appspot.com/x/.config?x=ad5163873ecfbc32 >> > dashboard link: https://syzkaller.appspot.com/bug?extid=87a05ae4accd500f5242 >> > compiler: gcc (GCC) 8.0.1 20180413 (experimental) >> > >> > Unfortunately, I don't have any reproducer for this crash yet. >> > >> > IMPORTANT: if you fix the bug, please add the following tag to the commit: >> > Reported-by: syzbot+87a05ae4accd500f5242@xxxxxxxxxxxxxxxxxxxxxxxxx >> > >> > INFO: task hung in do_page_mkwriteINFO: task syz-fuzzer:4876 blocked for >> > more than 140 seconds. >> > Not tainted 4.19.0-rc2-next-20180905+ #56 >> > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >> > syz-fuzzer D21704 4876 4871 0x00000000 >> > Call Trace: >> > context_switch kernel/sched/core.c:2825 [inline] >> > __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 >> > schedule+0xfb/0x450 kernel/sched/core.c:3517 >> > io_schedule+0x1c/0x70 kernel/sched/core.c:5140 >> > wait_on_page_bit_common mm/filemap.c:1100 [inline] >> > __lock_page+0x5b7/0x7a0 mm/filemap.c:1273 >> > lock_page include/linux/pagemap.h:483 [inline] >> > do_page_mkwrite+0x429/0x520 mm/memory.c:2391 >> >> Waiting for page lock after ->page_mkwrite callback. Which means >> ->page_mkwrite did not return VM_FAULT_LOCKED but 0. Looking into >> linux-next... indeed "fs: convert return type int to vm_fault_t" has busted >> block_page_mkwrite(). It has to return VM_FAULT_LOCKED and not 0 now. >> Souptick, can I ask you to run 'fstests' for at least common filesystems >> like ext4, xfs, btrfs when you change generic filesystem code please? That >> would catch a bug like this immediately. Thanks. >> > > "fs: convert return type int to vm_fault_t" is still under > review/discusson and not yet merge > into linux-next. I am not seeing it into linux-next tree.Can you > please share the commit id ? syzbot gave commit id in the report (see above)
