| From 59310ca797348ab935d4cd1986e2bbbfd5fe3597 Mon Sep 17 00:00:00 2001 |
| From: Dan Rosenberg <drosenberg@vsecurity.com> |
| Date: Wed, 23 Mar 2011 10:53:41 -0400 |
| Subject: [PATCH] sound/oss: remove offset from load_patch callbacks |
| |
| commit b769f49463711205d57286e64cf535ed4daf59e9 upstream. |
| |
| 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> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/sound/oss/dev_table.h b/sound/oss/dev_table.h |
| index b7617be..0199a31 100644 |
| --- a/sound/oss/dev_table.h |
| +++ b/sound/oss/dev_table.h |
| @@ -271,7 +271,7 @@ struct synth_operations |
| void (*reset) (int dev); |
| void (*hw_control) (int dev, unsigned char *event); |
| int (*load_patch) (int dev, int format, const char __user *addr, |
| - int offs, int count, int pmgr_flag); |
| + int count, int pmgr_flag); |
| void (*aftertouch) (int dev, int voice, int pressure); |
| void (*controller) (int dev, int voice, int ctrl_num, int value); |
| void (*panning) (int dev, int voice, int value); |
| diff --git a/sound/oss/midi_synth.c b/sound/oss/midi_synth.c |
| index 3bc7104..11685f1 100644 |
| --- a/sound/oss/midi_synth.c |
| +++ b/sound/oss/midi_synth.c |
| @@ -476,7 +476,7 @@ EXPORT_SYMBOL(midi_synth_hw_control); |
| |
| 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) |
| { |
| int orig_dev = synth_devs[dev]->midi_dev; |
| |
| @@ -491,33 +491,29 @@ midi_synth_load_patch(int dev, int format, const char __user *addr, |
| if (!prefix_cmd(orig_dev, 0xf0)) |
| return 0; |
| |
| + /* Invalid patch format */ |
| if (format != SYSEX_PATCH) |
| - { |
| -/* printk("MIDI Error: Invalid patch format (key) 0x%x\n", format);*/ |
| return -EINVAL; |
| - } |
| + |
| + /* Patch header too short */ |
| if (count < hdr_size) |
| - { |
| -/* printk("MIDI Error: Patch header too short\n");*/ |
| return -EINVAL; |
| - } |
| + |
| count -= hdr_size; |
| |
| /* |
| - * Copy the header from user space but ignore the first bytes which have |
| - * been transferred already. |
| + * Copy the header from user space |
| */ |
| |
| - if(copy_from_user(&((char *) &sysex)[offs], &(addr)[offs], hdr_size - offs)) |
| + if (copy_from_user(&sysex, addr, hdr_size)) |
| return -EFAULT; |
| - |
| - if (count < sysex.len) |
| - { |
| -/* printk(KERN_WARNING "MIDI Warning: Sysex record too short (%d<%d)\n", count, (int) sysex.len);*/ |
| + |
| + /* Sysex record too short */ |
| + if ((unsigned)count < (unsigned)sysex.len) |
| sysex.len = count; |
| - } |
| - left = sysex.len; |
| - src_offs = 0; |
| + |
| + left = sysex.len; |
| + src_offs = 0; |
| |
| for (i = 0; i < left && !signal_pending(current); i++) |
| { |
| diff --git a/sound/oss/midi_synth.h b/sound/oss/midi_synth.h |
| index 6bc9d00..b64ddd6 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); |
| diff --git a/sound/oss/opl3.c b/sound/oss/opl3.c |
| index f4ffdff..407cd67 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) |
| diff --git a/sound/oss/sequencer.c b/sound/oss/sequencer.c |
| index e85789e..a0072a9 100644 |
| --- a/sound/oss/sequencer.c |
| +++ b/sound/oss/sequencer.c |
| @@ -241,7 +241,7 @@ int sequencer_write(int dev, struct file *file, const char __user *buf, int coun |
| return -ENXIO; |
| |
| fmt = (*(short *) &event_rec[0]) & 0xffff; |
| - err = synth_devs[dev]->load_patch(dev, fmt, buf, p + 4, c, 0); |
| + err = synth_devs[dev]->load_patch(dev, fmt, buf + p, c, 0); |
| if (err < 0) |
| return err; |
| |
| -- |
| 1.7.4.4 |
| |