From: Jody Bruchon <[email protected]> On my AMD780V chipset, hda_intel.c can crash the kernel with a divide by zero for as-yet unknown reasons. A simple check for zero prevents it, though the problem that causes it remains. Since the workaround is harmless and won't affect anyone except victims of this bug, it should be safe; moreover, because this crash can be triggered by a user-mode application, there are denial of service implications on the systems affected by the bug without the patch.
Signed-off-by: Jody Bruchon <[email protected]> Cc: <[email protected]> Signed-off-by: Takashi Iwai <[email protected]> sound/pci/hda/hda_intel.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) --- http://git.linuxtv.org/v4l-dvb.git?a=commitdiff;h=fed08d036f2aabd8d0c684439de37f8ebec2bbc2 diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index b8faa6d..e767c3f 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1893,6 +1893,12 @@ static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev) if (!bdl_pos_adj[chip->dev_index]) return 1; /* no delayed ack */ + if (azx_dev->period_bytes == 0) { + printk(KERN_WARNING + "hda-intel: Divide by zero was avoided " + "in azx_dev->period_bytes.\n"); + return 0; + } if (pos % azx_dev->period_bytes > azx_dev->period_bytes / 2) return 0; /* NG - it's below the period boundary */ return 1; /* OK, it's fine */ _______________________________________________ linuxtv-commits mailing list [email protected] http://www.linuxtv.org/cgi-bin/mailman/listinfo/linuxtv-commits
