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authorDan Rosenberg <drosenberg@vsecurity.com>2011-03-23 10:53:41 -0400
committerTakashi Iwai <tiwai@suse.de>2011-03-23 22:47:46 +0100
commitb769f49463711205d57286e64cf535ed4daf59e9 (patch)
tree1c674fdbed533434d2ba9b7b1b3646243160e55c /sound/oss/opl3.c
parentce24f58a1187ca3058d72c3f897e3b574209ab20 (diff)
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 <drosenberg@vsecurity.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/oss/opl3.c')
-rw-r--r--sound/oss/opl3.c8
1 files changed, 2 insertions, 6 deletions
diff --git a/sound/oss/opl3.c b/sound/oss/opl3.c
index 938c48c43585..cbf957424d5c 100644
--- a/sound/oss/opl3.c
+++ b/sound/oss/opl3.c
@@ -820,7 +820,7 @@ static void opl3_hw_control(int dev, unsigned char *event)
}
static int opl3_load_patch(int dev, int format, const char __user *addr,
- int offs, int count, int pmgr_flag)
+ int count, int pmgr_flag)
{
struct sbi_instrument ins;
@@ -830,11 +830,7 @@ static int opl3_load_patch(int dev, int format, const char __user *addr,
return -EINVAL;
}
- /*
- * What the fuck is going on here? We leave junk in the beginning
- * of ins and then check the field pretty close to that beginning?
- */
- if(copy_from_user(&((char *) &ins)[offs], addr + offs, sizeof(ins) - offs))
+ if (copy_from_user(&ins, addr, sizeof(ins)))
return -EFAULT;
if (ins.channel < 0 || ins.channel >= SBFM_MAXINSTR)