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authorOleg Nesterov <oleg@redhat.com>2013-09-11 17:24:45 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-11 18:59:07 -0400
commit4e0621a07ea58a0dc15859be3b743bdeb194a51b (patch)
tree954721cb1776b325b74a48b1858d1b0ac6ff580b
parentcb7b6b1cbc20a970c7124efae1c2478155604b54 (diff)
exec: don't retry if request_module() fails
A separate one-liner for better documentation. It doesn't make sense to retry if request_module() fails to exec /sbin/modprobe, add the additional "request_module() < 0" check. However, this logic still doesn't look exactly right: 1. It would be better to check "request_module() != 0", the user space modprobe process should report the correct exit code. But I didn't dare to add the user-visible change. 2. The whole ENOEXEC logic looks suboptimal. Suppose that we try to exec a "#!path-to-unsupported-binary" script. In this case request_module() + "retry" will be done twice: first by the "depth == 1" code, and then again by the "depth == 0" caller which doesn't make sense. 3. And note that in the case above bprm->buf was already changed by load_script()->prepare_binprm(), so this looks even more ugly. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/exec.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/exec.c b/fs/exec.c
index ba357e6aea98..635b586de336 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1418,7 +1418,8 @@ int search_binary_handler(struct linux_binprm *bprm)
1418 if (printable(bprm->buf[0]) && printable(bprm->buf[1]) && 1418 if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
1419 printable(bprm->buf[2]) && printable(bprm->buf[3])) 1419 printable(bprm->buf[2]) && printable(bprm->buf[3]))
1420 return retval; 1420 return retval;
1421 request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)); 1421 if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
1422 return retval;
1422 need_retry = false; 1423 need_retry = false;
1423 goto retry; 1424 goto retry;
1424 } 1425 }