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| author | Kenneth Lee <kenlee@dg.gov.cn> | 2006-09-16 12:15:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-16 12:54:32 -0700 |
| commit | e4b69aa2a1bcee21f8d5e089b8682dd8aaace5eb (patch) | |
| tree | ccc3ff548d892965999d2ec2d64617e6daff41ac /kernel/kmod.c | |
| parent | 1ab7a1f3b496aae5b1e062a6f50d62830c248190 (diff) | |
| download | lwn-e4b69aa2a1bcee21f8d5e089b8682dd8aaace5eb.tar.gz lwn-e4b69aa2a1bcee21f8d5e089b8682dd8aaace5eb.zip | |
[PATCH] bug fix in kernel/kmod.c
I think there is a bug in kmod.c: In __call_usermodehelper(), when
kernel_thread(wait_for_helper, ...) return success, since wait_for_helper()
might call complete() at any time, the sub_info should not be used any
more.
Normally wait_for_helper() take a long time to finish, you may not get
problem for most of the case. But if you remove /sbin/modprobe, it may
become easier for you to get a oop in khelper.
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/kmod.c')
| -rw-r--r-- | kernel/kmod.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c index 1d32defa38ab..5c470c57fb57 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -197,11 +197,12 @@ static void __call_usermodehelper(void *data) { struct subprocess_info *sub_info = data; pid_t pid; + int wait = sub_info->wait; /* CLONE_VFORK: wait until the usermode helper has execve'd * successfully We need the data structures to stay around * until that is done. */ - if (sub_info->wait) + if (wait) pid = kernel_thread(wait_for_helper, sub_info, CLONE_FS | CLONE_FILES | SIGCHLD); else @@ -211,7 +212,7 @@ static void __call_usermodehelper(void *data) if (pid < 0) { sub_info->retval = pid; complete(sub_info->complete); - } else if (!sub_info->wait) + } else if (!wait) complete(sub_info->complete); } |