Messages in this thread | | | Date | Wed, 17 Feb 2021 16:15:39 +0100 | From | Greg KH <> | Subject | Re: [PATCH] tty: fix when iov_iter_count() returns 0 in tty_write() |
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On Wed, Feb 17, 2021 at 04:13:58PM +0100, Greg KH wrote: > On Wed, Feb 17, 2021 at 08:43:47PM +0600, Sabyrzhan Tasbolatov wrote: > > syzbot found WARNING in iov_iter_revert[1] when iov_iter_count() returns 0, > > therefore INT_MAX is passed to iov_iter_revert() causing > MAX_RW_COUNT > > warning. > > > > static inline ssize_t do_tty_write() > > { > > .. > > size_t count = iov_iter_count(from); > > .. > > size_t size = count; > > if (ret != size) > > iov_iter_revert(from, size-ret); > > > > [1] WARNING: lib/iov_iter.c:1090 > > Call Trace: > > do_tty_write drivers/tty/tty_io.c:967 [inline] > > file_tty_write.constprop.0+0x55f/0x8f0 drivers/tty/tty_io.c:1048 > > call_write_iter include/linux/fs.h:1901 [inline] > > new_sync_write+0x426/0x650 fs/read_write.c:518 > > vfs_write+0x791/0xa30 fs/read_write.c:605 > > ksys_write+0x12d/0x250 fs/read_write.c:658 > > > > Fixes: 494e63ee9c("tty: implement write_iter") > > Nit, you need a ' ' before your '(' character here, otherwise the > linux-next scripts will complain.
Also, you got the git commit id wrong, so this needs to be fixed up anyway. You are pointing to a merge point, I doubt that's what you want to point to here, right?
thanks,
greg k-h
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