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| author | Jann Horn <jannh@google.com> | 2022-04-05 18:39:31 +0200 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-04-06 15:09:33 +0200 |
| commit | 1448769c9cdb69ad65287f4f7ab58bc5f2f5d7ba (patch) | |
| tree | 457e2d91ba4a10facd9e511015c6808e6bc64709 /drivers/char/random.c | |
| parent | random: do not allow user to keep crng key around on stack (diff) | |
| download | linux-1448769c9cdb69ad65287f4f7ab58bc5f2f5d7ba.tar.xz linux-1448769c9cdb69ad65287f4f7ab58bc5f2f5d7ba.zip | |
random: check for signal_pending() outside of need_resched() check
signal_pending() checks TIF_NOTIFY_SIGNAL and TIF_SIGPENDING, which
signal that the task should bail out of the syscall when possible. This
is a separate concept from need_resched(), which checks
TIF_NEED_RESCHED, signaling that the task should preempt.
In particular, with the current code, the signal_pending() bailout
probably won't work reliably.
Change this to look like other functions that read lots of data, such as
read_zero().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to '')
| -rw-r--r-- | drivers/char/random.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 47f01b1482a9..394cbd814a0b 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -549,13 +549,13 @@ static ssize_t get_random_bytes_user(void __user *buf, size_t nbytes) } do { - if (large_request && need_resched()) { + if (large_request) { if (signal_pending(current)) { if (!ret) ret = -ERESTARTSYS; break; } - schedule(); + cond_resched(); } chacha20_block(chacha_state, output); |