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| author | Eric Paris <eparis@redhat.com> | 2009-01-27 11:50:37 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-27 07:37:15 -0800 |
| commit | 808ffa3d302257b9dc37b1412c1fcdf976fcddac (patch) | |
| tree | 9d6d6de93da50d6c2df3cc7b0052a189f410a076 /drivers/char | |
| parent | 5ee810072175042775e39bdd3eaaa68884c27805 (diff) | |
| download | linux-808ffa3d302257b9dc37b1412c1fcdf976fcddac.tar.gz linux-808ffa3d302257b9dc37b1412c1fcdf976fcddac.tar.bz2 linux-808ffa3d302257b9dc37b1412c1fcdf976fcddac.zip | |
tty_open can return to userspace holding tty_mutex
__tty_open could return (to userspace) holding the tty_mutex thanks to a
regression introduced by 4a2b5fddd53b80efcb3266ee36e23b8de28e761a ("Move
tty lookup/reopen to caller").
This was found by bisecting an fsfuzzer problem. Admittedly I have no
idea how it managed to tickle this 100% reliably, but it is clearly a
regression and when hit leaves the box in a completely unusable state.
This patch lets the fsfuzzer test complete every time.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tty_io.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index d33e5ab06177..bc84e125c6bc 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1817,8 +1817,10 @@ got_driver: /* check whether we're reopening an existing tty */ tty = tty_driver_lookup_tty(driver, inode, index); - if (IS_ERR(tty)) + if (IS_ERR(tty)) { + mutex_unlock(&tty_mutex); return PTR_ERR(tty); + } } if (tty) { |