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| author | Oleg Nesterov <oleg@redhat.com> | 2014-01-23 15:55:49 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-23 16:37:02 -0800 |
| commit | 83f62a2eacb1d6945c78523f20e0c34b5d94913c (patch) | |
| tree | e42b10740afd8489319388018fa1d6d10be22482 /fs/exec.c | |
| parent | 68ce670b6e8edc30551862e7f6a306e45389e189 (diff) | |
| download | lwn-83f62a2eacb1d6945c78523f20e0c34b5d94913c.tar.gz lwn-83f62a2eacb1d6945c78523f20e0c34b5d94913c.zip | |
exec:check_unsafe_exec: use while_each_thread() rather than next_thread()
next_thread() should be avoided, change check_unsafe_exec() to use
while_each_thread().
Nobody except signal->curr_target actually needs next_thread-like code,
and we need to change (fix) this interface. This particular code is fine,
p == current. But in general the code like this can loop forever if p
exits and next_thread(t) can't reach the unhashed thread.
This also saves 32 bytes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/exec.c b/fs/exec.c index 9cbad5b0187e..81ae6212187a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1243,10 +1243,11 @@ static int check_unsafe_exec(struct linux_binprm *bprm) if (current->no_new_privs) bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS; + t = p; n_fs = 1; spin_lock(&p->fs->lock); rcu_read_lock(); - for (t = next_thread(p); t != p; t = next_thread(t)) { + while_each_thread(p, t) { if (t->fs == p->fs) n_fs++; } |