3.2.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jiang Liu <liuj97@xxxxxxxxx> commit 5863e10b441e7ea4b492f930f1be180a97d026f3 upstream. Use zram->init_lock to protect access to zram->meta, otherwise it may cause invalid memory access if zram->meta has been freed by zram_reset_device(). This issue may be triggered by: Thread 1: while true; do cat mem_used_total; done Thread 2: while true; do echo 8M > disksize; echo 1 > reset; done Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/staging/zram/zram_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/staging/zram/zram_sysfs.c +++ b/drivers/staging/zram/zram_sysfs.c @@ -186,10 +186,12 @@ static ssize_t mem_used_total_show(struc u64 val = 0; struct zram *zram = dev_to_zram(dev); + down_read(&zram->init_lock); if (zram->init_done) { val = xv_get_total_size_bytes(zram->mem_pool) + ((u64)(zram->stats.pages_expand) << PAGE_SHIFT); } + up_read(&zram->init_lock); return sprintf(buf, "%llu\n", val); } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html