The patch titled
exec: do not call request_module() twice from search_binary_handler()
has been added to the -mm tree. Its filename is
exec-do-not-call-request_module-twice-from-search_binary_handler.patch
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------------------------------------------------------
Subject: exec: do not call request_module() twice from search_binary_handler()
From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Currently, search_binary_handler() tries to load binary loader module
using request_module() if a loader for the requested program is not yet
loaded. But second attempt of request_module() does not affect the result
of search_binary_handler().
If request_module() triggered recursion, calling request_module() twice
causes 2 to the power of MAX_KMOD_CONCURRENT (= 50) repetitions. It is
not an infinite loop but is sufficient for users to consider as a hang up.
Therefore, this patch changes not to call request_module() twice, making 1
to the power of MAX_KMOD_CONCURRENT repetitions in case of recursion.
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Reported-by: Richard Weinberger <richard@xxxxxx>
Tested-by: Richard Weinberger <richard@xxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 2 ++
1 file changed, 2 insertions(+)
diff -puN fs/exec.c~exec-do-not-call-request_module-twice-from-search_binary_handler fs/exec.c
--- a/fs/exec.c~exec-do-not-call-request_module-twice-from-search_binary_handler
+++ a/fs/exec.c
@@ -1432,6 +1432,8 @@ int search_binary_handler(struct linux_b
printable(bprm->buf[2]) &&
printable(bprm->buf[3]))
break; /* -ENOEXEC */
+ if (try)
+ break; /* -ENOEXEC */
request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
#endif
}
_
Patches currently in -mm which might be from penguin-kernel@xxxxxxxxxxxxxxxxxxx are
linux-next.patch
exec-do-not-call-request_module-twice-from-search_binary_handler.patch
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