diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2013-09-11 14:24:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-11 15:59:04 -0700 |
| commit | 131b2f9f1214f338f0bf7c0d9760019f2b1d0c20 (patch) | |
| tree | b60a498414e259fe4e81f210378538f90ada9224 | |
| parent | 5d1baf3b63bfc8c709dc44df85ff1475c7ef489d (diff) | |
exec: kill "int depth" in search_binary_handler()
Nobody except search_binary_handler() should touch ->recursion_depth, "int
depth" buys nothing but complicates the code, kill it.
Probably we should also kill "fn" and the !NULL check, ->load_binary
should be always defined. And it can not go away after read_unlock() or
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>
| -rw-r--r-- | fs/exec.c | 9 | ||||
| -rw-r--r-- | include/linux/binfmts.h | 2 |
2 files changed, 5 insertions, 6 deletions
diff --git a/fs/exec.c b/fs/exec.c index 4d95b4709ea..b6e35ec818a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1370,12 +1370,11 @@ EXPORT_SYMBOL(remove_arg_zero); */ int search_binary_handler(struct linux_binprm *bprm) { - unsigned int depth = bprm->recursion_depth; - int try,retval; + int try, retval; struct linux_binfmt *fmt; /* This allows 4 levels of binfmt rewrites before failing hard. */ - if (depth > 5) + if (bprm->recursion_depth > 5) return -ELOOP; retval = security_bprm_check(bprm); @@ -1396,9 +1395,9 @@ int search_binary_handler(struct linux_binprm *bprm) if (!try_module_get(fmt->module)) continue; read_unlock(&binfmt_lock); - bprm->recursion_depth = depth + 1; + bprm->recursion_depth++; retval = fn(bprm); - bprm->recursion_depth = depth; + bprm->recursion_depth--; if (retval >= 0) { put_binfmt(fmt); allow_write_access(bprm->file); diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 70cf138690e..e8112ae5053 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -31,7 +31,7 @@ struct linux_binprm { #ifdef __alpha__ unsigned int taso:1; #endif - unsigned int recursion_depth; + unsigned int recursion_depth; /* only for search_binary_handler() */ struct file * file; struct cred *cred; /* new credentials */ int unsafe; /* how unsafe this exec is (mask of LSM_UNSAFE_*) */ |