syzbot reported a use-after-free Read in ext4_find_extent that is hit when
using a corrupted file system. The bug was reported on Android 5.15, but
using the same reproducer triggers the bug on v6.2-rc1 as well.
Fix the use-after-free by checking the extent header magic. An alternative
would be to check the values of EXT4_{FIRST,LAST}_{EXTENT,INDEX} used in
ext4_ext_binsearch() and ext4_ext_binsearch_idx(), so that we make sure
that pointers returned by EXT4_{FIRST,LAST}_{EXTENT,INDEX} don't exceed the
bounds of the extent tree node. But this alternative will not squash
the bug for the cases where eh->eh_entries fit into eh->eh_max. We could
also try to check the sanity of the path, but costs more than checking just
the header magic, so stick to the header magic sanity check.
Link: https://syzkaller.appspot.com/bug?id=be6e90ce70987950e6deb3bac8418344ca8b96…
Reported-by: syzbot+0827b4b52b5ebf65f219(a)syzkaller.appspotmail.com
Cc: stable(a)vger.kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)linaro.org>
---
v2: drop wrong/uneeded le16_to_cpu() conversion for eh->eh_magic
fs/ext4/extents.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 9de1c9d1a13d..bedc8c098449 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -894,6 +894,12 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
gfp_flags |= __GFP_NOFAIL;
eh = ext_inode_hdr(inode);
+ if (eh->eh_magic != EXT4_EXT_MAGIC) {
+ EXT4_ERROR_INODE(inode, "Extent header has invalid magic.");
+ ret = -EFSCORRUPTED;
+ goto err;
+ }
+
depth = ext_depth(inode);
if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
--
2.34.1
These indices should reference the ID placed within the dai_driver
array, not the indices of the array itself.
This fixes commit 4ff028f6c108 ("ASoC: qcom: lpass-cpu: Make I2S SD
lines configurable"), which among others, broke IPQ8064 audio
(sound/soc/qcom/lpass-ipq806x.c) because it uses ID 4 but we'd stop
initializing the mi2s_playback_sd_mode and mi2s_capture_sd_mode arrays
at ID 0.
Fixes: 4ff028f6c108 ("ASoC: qcom: lpass-cpu: Make I2S SD lines configurable")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Brian Norris <computersforpeace(a)gmail.com>
---
sound/soc/qcom/lpass-cpu.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/sound/soc/qcom/lpass-cpu.c b/sound/soc/qcom/lpass-cpu.c
index 54353842dc07..dbdaaa85ce48 100644
--- a/sound/soc/qcom/lpass-cpu.c
+++ b/sound/soc/qcom/lpass-cpu.c
@@ -1037,10 +1037,11 @@ static void of_lpass_cpu_parse_dai_data(struct device *dev,
struct lpass_data *data)
{
struct device_node *node;
- int ret, id;
+ int ret, i, id;
/* Allow all channels by default for backwards compatibility */
- for (id = 0; id < data->variant->num_dai; id++) {
+ for (i = 0; i < data->variant->num_dai; i++) {
+ id = data->variant->dai_driver[i].id;
data->mi2s_playback_sd_mode[id] = LPAIF_I2SCTL_MODE_8CH;
data->mi2s_capture_sd_mode[id] = LPAIF_I2SCTL_MODE_8CH;
}
--
2.39.0