Revision 993dfa8776308dcfd311cf77a3bbed4aa11e9868 authored by Trond Myklebust on 31 March 2006, 10:30:55 UTC, committed by Linus Torvalds on 31 March 2006, 20:18:56 UTC
sys_flock() currently has a race which can result in a double free in the multi-thread case. Thread 1 Thread 2 sys_flock(file, LOCK_EX) sys_flock(file, LOCK_UN) If Thread 2 removes the lock from inode->i_lock before Thread 1 tests for list_empty(&lock->fl_link) at the end of sys_flock, then both threads will end up calling locks_free_lock for the same lock. Fix is to make flock_lock_file() do the same as posix_lock_file(), namely to make a copy of the request, so that the caller can always free the lock. This also has the side-effect of fixing up a reference problem in the lockd handling of flock. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent 7a2bd3f