From b769f49463711205d57286e64cf535ed4daf59e9 Mon Sep 17 00:00:00 2001 From: Dan Rosenberg Date: Wed, 23 Mar 2011 10:53:41 -0400 Subject: sound/oss: remove offset from load_patch callbacks Was: [PATCH] sound/oss/midi_synth: prevent underflow, use of uninitialized value, and signedness issue The offset passed to midi_synth_load_patch() can be essentially arbitrary. If it's greater than the header length, this will result in a copy_from_user(dst, src, negative_val). While this will just return -EFAULT on x86, on other architectures this may cause memory corruption. Additionally, the length field of the sysex_info structure may not be initialized prior to its use. Finally, a signed comparison may result in an unintentionally large loop. On suggestion by Takashi Iwai, version two removes the offset argument from the load_patch callbacks entirely, which also resolves similar issues in opl3. Compile tested only. v3 adjusts comments and hopefully gets copy offsets right. Signed-off-by: Dan Rosenberg Signed-off-by: Takashi Iwai --- sound/oss/midi_synth.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'sound/oss/midi_synth.h') diff --git a/sound/oss/midi_synth.h b/sound/oss/midi_synth.h index 6bc9d00bc77..b64ddd6c4ab 100644 --- a/sound/oss/midi_synth.h +++ b/sound/oss/midi_synth.h @@ -8,7 +8,7 @@ int midi_synth_open (int dev, int mode); void midi_synth_close (int dev); void midi_synth_hw_control (int dev, unsigned char *event); int midi_synth_load_patch (int dev, int format, const char __user * addr, - int offs, int count, int pmgr_flag); + int count, int pmgr_flag); void midi_synth_panning (int dev, int channel, int pressure); void midi_synth_aftertouch (int dev, int channel, int pressure); void midi_synth_controller (int dev, int channel, int ctrl_num, int value); -- cgit v1.2.3-70-g09d2