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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2011-07-26 16:08:41 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-10-16 14:14:54 -0700 |
| commit | 2b7eea63de50d738ae12a1bf84b76ef91c007a0e (patch) | |
| tree | ec24a34af3ec3ae142b0d2c84e22d7b264326b30 /fs | |
| parent | 6770fa9b440e57ea2a7c586063c5c30da2933513 (diff) | |
| download | lwn-2b7eea63de50d738ae12a1bf84b76ef91c007a0e.tar.gz lwn-2b7eea63de50d738ae12a1bf84b76ef91c007a0e.zip | |
exec: do not call request_module() twice from search_binary_handler()
commit 912193521b719fbfc2f16776febf5232fe8ba261 upstream.
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@I-love.SAKURA.ne.jp>
Reported-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Maxim Uvarov <muvarov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/exec.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/exec.c b/fs/exec.c index 6075a1e727ae..044c13ffdc42 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1411,6 +1411,8 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) printable(bprm->buf[2]) && printable(bprm->buf[3])) break; /* -ENOEXEC */ + if (try) + break; /* -ENOEXEC */ request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); #endif } |