[PATCH] Fix infinite loop in search_binary_handler()

From: Richard Weinberger
Date: Thu Jun 16 2011 - 18:12:10 EST

When search_binary_handler() is called to find a handler
for /sbin/modprobe it will end up in an infinite loop because
it executes request_module() to load a binfmt module with

Running a x86_64 kernel without ia32 emulation and a x86 user land
triggers this issue.

Signed-off-by: Richard Weinberger <richard@xxxxxx>
fs/exec.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 97e0d52..7271b22 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1411,7 +1411,10 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
printable(bprm->buf[2]) &&
break; /* -ENOEXEC */
- request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
+ /* Avoid an infinite loop */
+ if (strcmp(modprobe_path, bprm->filename))
+ request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));

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