On 8/5/22 1:25 AM, Saurabh Sengar wrote:
Current code produces a warning as shown below when total characters in the constituent block device names plus the slashes exceeds 200. snprintf() returns the number of characters generated from the given input, which could cause the expression “200 – len” to wrap around to a large positive number. Fix this by using scnprintf() instead, which returns the actual number of characters written into the buffer. [ 1513.267938] ------------[ cut here ]------------ [ 1513.267943] WARNING: CPU: 15 PID: 37247 at <snip>/lib/vsprintf.c:2509 vsnprintf+0x2c8/0x510 [ 1513.267944] Modules linked in: <snip> [ 1513.267969] CPU: 15 PID: 37247 Comm: mdadm Not tainted 5.4.0-1085-azure #90~18.04.1-Ubuntu [ 1513.267969] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022 [ 1513.267971] RIP: 0010:vsnprintf+0x2c8/0x510 <-snip-> [ 1513.267982] Call Trace: [ 1513.267986] snprintf+0x45/0x70 [ 1513.267990] ? disk_name+0x71/0xa0 [ 1513.267993] dump_zones+0x114/0x240 [raid0] [ 1513.267996] ? _cond_resched+0x19/0x40 [ 1513.267998] raid0_run+0x19e/0x270 [raid0] [ 1513.268000] md_run+0x5e0/0xc50 [ 1513.268003] ? security_capable+0x3f/0x60 [ 1513.268005] do_md_run+0x19/0x110 [ 1513.268006] md_ioctl+0x195e/0x1f90 [ 1513.268007] blkdev_ioctl+0x91f/0x9f0 [ 1513.268010] block_ioctl+0x3d/0x50 [ 1513.268012] do_vfs_ioctl+0xa9/0x640 [ 1513.268014] ? __fput+0x162/0x260 [ 1513.268016] ksys_ioctl+0x75/0x80 [ 1513.268017] __x64_sys_ioctl+0x1a/0x20 [ 1513.268019] do_syscall_64+0x5e/0x200 [ 1513.268021] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 766038846e875 ("md/raid0: replace printk() with pr_*()") Signed-off-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> --- drivers/md/raid0.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index b21e101..b6f0fc1 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -48,7 +48,7 @@ static void dump_zones(struct mddev *mddev) int len = 0;for (k = 0; k < conf->strip_zone[j].nb_dev; k++)- len += snprintf(line+len, 200-len, "%s%s", k?"/":"", + len += scnprintf(line+len, 200-len, "%s%s", k?"/":"", bdevname(conf->devlist[j*raid_disks + k]->bdev, b)); pr_debug("md: zone%d=[%s]\n", j, line);
Acked-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx> Thanks, Guoqing
