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authorOleg Nesterov <oleg@redhat.com>2013-09-11 14:24:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-11 15:59:05 -0700
commit92eaa565add62d56b90987f58ea9feafc5a7c183 (patch)
tree78f7bfaa0b99b2b2f5b554bc883b67ac68412e21 /fs/exec.c
parent52f14282bb0c3d3e5ba2a9eaacb12ff37a033e7e (diff)
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exec: kill ->load_binary != NULL check in search_binary_handler()
search_binary_handler() checks ->load_binary != NULL for no reason, this method should be always defined. Turn this check into WARN_ON() and move it into __register_binfmt(). Also, kill the function pointer. The current code looks confusing, as if ->load_binary can go away after read_unlock(&binfmt_lock). But we rely on module_get(fmt->module), this fmt can't be changed or unregistered, otherwise this code is buggy anyway. 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>
Diffstat (limited to 'fs/exec.c')
-rw-r--r--fs/exec.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/exec.c b/fs/exec.c
index a4cfd1d725e0..7b92fbfa63aa 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -74,6 +74,8 @@ static DEFINE_RWLOCK(binfmt_lock);
void __register_binfmt(struct linux_binfmt * fmt, int insert)
{
BUG_ON(!fmt);
+ if (WARN_ON(!fmt->load_binary))
+ return;
write_lock(&binfmt_lock);
insert ? list_add(&fmt->lh, &formats) :
list_add_tail(&fmt->lh, &formats);
@@ -1389,14 +1391,11 @@ int search_binary_handler(struct linux_binprm *bprm)
for (try=0; try<2; try++) {
read_lock(&binfmt_lock);
list_for_each_entry(fmt, &formats, lh) {
- int (*fn)(struct linux_binprm *) = fmt->load_binary;
- if (!fn)
- continue;
if (!try_module_get(fmt->module))
continue;
read_unlock(&binfmt_lock);
bprm->recursion_depth++;
- retval = fn(bprm);
+ retval = fmt->load_binary(bprm);
bprm->recursion_depth--;
if (retval >= 0) {
put_binfmt(fmt);