The patch titled dma-debug: fix check_unmap null pointer dereference has been removed from the -mm tree. Its filename was dma-debug-fix-check_unmap-null-pointer-dereference.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: dma-debug: fix check_unmap null pointer dereference From: Kyle McMartin <kyle@xxxxxxxxxx> While it's debatable whether or not a NULL device argument to the DMA API functions is valid... since it certainly isn't valid on devices with an IOMMU... dma-debug really shouldn't be dereferencing null pointers either. Guard against that in err_printk and the driver_filter functions. A Fedora rawhide user was seeing this in one of the dvb drivers resulting in an oops on boot. A patch has been sent for testing to the driver, but I feel the dma debugging support should be fixed as well. (There's still a pile of legacy garbage in the kernel passing null pointers to dma_{alloc,free}_*. :( Signed-off-by: Kyle McMartin <kyle@xxxxxxxxxx> Cc: Joerg Roedel <joerg.roedel@xxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/dma-debug.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff -puN lib/dma-debug.c~dma-debug-fix-check_unmap-null-pointer-dereference lib/dma-debug.c --- a/lib/dma-debug.c~dma-debug-fix-check_unmap-null-pointer-dereference +++ a/lib/dma-debug.c @@ -156,9 +156,13 @@ static bool driver_filter(struct device return true; /* driver filter on and initialized */ - if (current_driver && dev->driver == current_driver) + if (current_driver && dev && dev->driver == current_driver) return true; + /* driver filter on, but we can't filter on a NULL device... */ + if (!dev) + return false; + if (current_driver || !current_driver_name[0]) return false; @@ -183,17 +187,17 @@ static bool driver_filter(struct device return ret; } -#define err_printk(dev, entry, format, arg...) do { \ - error_count += 1; \ - if (driver_filter(dev) && \ - (show_all_errors || show_num_errors > 0)) { \ - WARN(1, "%s %s: " format, \ - dev_driver_string(dev), \ - dev_name(dev) , ## arg); \ - dump_entry_trace(entry); \ - } \ - if (!show_all_errors && show_num_errors > 0) \ - show_num_errors -= 1; \ +#define err_printk(dev, entry, format, arg...) do { \ + error_count += 1; \ + if (driver_filter(dev) && \ + (show_all_errors || show_num_errors > 0)) { \ + WARN(1, "%s %s: " format, \ + dev ? dev_driver_string(dev) : "NULL", \ + dev ? dev_name(dev) : "NULL", ## arg); \ + dump_entry_trace(entry); \ + } \ + if (!show_all_errors && show_num_errors > 0) \ + show_num_errors -= 1; \ } while (0); /* _ Patches currently in -mm which might be from kyle@xxxxxxxxxx are linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html