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| author | Mateusz Nosek <mateusznosek0@gmail.com> | 2020-09-27 02:08:58 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-10-28 15:48:51 +0100 |
| commit | 921c7ebd1337d1a46783d7e15a850e12aed2eaa0 (patch) | |
| tree | 9b4401cb0791023cb74c27a94633ccbf7691d1cf /kernel/futex.c | |
| parent | lockdep: Fix preemption WARN for spurious IRQ-enable (diff) | |
| download | linux-921c7ebd1337d1a46783d7e15a850e12aed2eaa0.tar.xz linux-921c7ebd1337d1a46783d7e15a850e12aed2eaa0.zip | |
futex: Fix incorrect should_fail_futex() handling
If should_futex_fail() returns true in futex_wake_pi(), then the 'ret'
variable is set to -EFAULT and then immediately overwritten. So the failure
injection is non-functional.
Fix it by actually leaving the function and returning -EFAULT.
The Fixes tag is kinda blury because the initial commit which introduced
failure injection was already sloppy, but the below mentioned commit broke
it completely.
[ tglx: Massaged changelog ]
Fixes: 6b4f4bc9cb22 ("locking/futex: Allow low-level atomic operations to return -EAGAIN")
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200927000858.24219-1-mateusznosek0@gmail.com
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index a5876694a60e..39681bf8b06c 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1502,8 +1502,10 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ */ newval = FUTEX_WAITERS | task_pid_vnr(new_owner); - if (unlikely(should_fail_futex(true))) + if (unlikely(should_fail_futex(true))) { ret = -EFAULT; + goto out_unlock; + } ret = cmpxchg_futex_value_locked(&curval, uaddr, uval, newval); if (!ret && (curval != uval)) { |