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| author |   Clemens Ladisch <clemens@ladisch.de> | 2010-10-15 12:06:18 +0200 |
|---|---|---|
| committer |   Takashi Iwai <tiwai@suse.de> | 2010-10-17 10:11:40 +0200 |
| commit | aa73aec6c385e2c797ac25cc7ccf0318031de7c8 (patch) | |
| tree | 97ab3c6e917c2592f2c432c703a058ac0cebc574 /sound/core/rawmidi.c | |
| parent | Linux 2.6.36-rc8 (diff) | |
| download | linux-dev-aa73aec6c385e2c797ac25cc7ccf0318031de7c8.tar.xz linux-dev-aa73aec6c385e2c797ac25cc7ccf0318031de7c8.zip | |
ALSA: rawmidi: fix oops (use after free) when unloading a driver module
When a driver module is unloaded and the last still open file is a raw
MIDI device, the card and its devices will be actually freed in the
snd_card_file_remove() call when that file is closed. Afterwards, rmidi
and rmidi->card point into freed memory, so the module pointer is likely
to be garbage.
(This was introduced by commit 9a1b64caac82aa02cb74587ffc798e6f42c6170a.)
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Reported-by: Krzysztof Foltman <wdev@foltman.com>
Cc: 2.6.30-2.6.35 <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/rawmidi.c')
| -rw-r--r-- | sound/core/rawmidi.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index a7868ad4d530..cbbed0db9e56 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -535,13 +535,15 @@ static int snd_rawmidi_release(struct inode *inode, struct file *file) { struct snd_rawmidi_file *rfile; struct snd_rawmidi *rmidi; + struct module *module; rfile = file->private_data; rmidi = rfile->rmidi; rawmidi_release_priv(rfile); kfree(rfile); + module = rmidi->card->module; snd_card_file_remove(rmidi->card, file); - module_put(rmidi->card->module); + module_put(module); return 0; } |