summaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorEric W. Biederman <ebiederm@xmission.com>2021-09-03 10:26:05 -0500
committerEric W. Biederman <ebiederm@xmission.com>2021-10-06 11:27:55 -0500
commit7e3c4fb7fc19bcf20657de3edb718ec1b26c7df3 (patch)
tree4105e71b67facde85813e97980122b6df56f0b34 /fs
parent4f627af8e6068892cafe031df6c14e8a0aaaa426 (diff)
downloadlinux-7e3c4fb7fc19bcf20657de3edb718ec1b26c7df3.tar.gz
exec: Check for a pending fatal signal instead of core_state
Prevent exec continuing when a fatal signal is pending by replacing mmap_read_lock with mmap_read_lock_killable. This is always the right thing to do as userspace will never observe an exec complete when there is a fatal signal pending. With that change it becomes unnecessary to explicitly test for a core dump in progress. In coredump_wait zap_threads arranges under mmap_write_lock for all tasks that use a mm to also have SIGKILL pending, which means mmap_read_lock_killable will always return -EINTR when old_mm->core_state is present. Link: https://lkml.kernel.org/r/87fstux27w.fsf@disp2133 Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/exec.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/fs/exec.c b/fs/exec.c
index a098c133d8d7..b6079f1a098e 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -987,16 +987,14 @@ static int exec_mmap(struct mm_struct *mm)
if (old_mm) {
/*
- * Make sure that if there is a core dump in progress
- * for the old mm, we get out and die instead of going
- * through with the exec. We must hold mmap_lock around
- * checking core_state and changing tsk->mm.
+ * If there is a pending fatal signal perhaps a signal
+ * whose default action is to create a coredump get
+ * out and die instead of going through with the exec.
*/
- mmap_read_lock(old_mm);
- if (unlikely(old_mm->core_state)) {
- mmap_read_unlock(old_mm);
+ ret = mmap_read_lock_killable(old_mm);
+ if (ret) {
up_write(&tsk->signal->exec_update_lock);
- return -EINTR;
+ return ret;
}
}