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_*()")
Reviewed-by: Michael Kelley <[email protected]>
Acked-by: Guoqing Jiang <[email protected]>
Signed-off-by: Saurabh Sengar <[email protected]>
---
V2 :
- Rebase
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 78addfe..857c493 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -47,7 +47,7 @@ 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%pg", k?"/":"",
+ len += scnprintf(line+len, 200-len, "%s%pg", k?"/":"",
conf->devlist[j * raid_disks + k]->bdev);
pr_debug("md: zone%d=[%s]\n", j, line);
--
1.8.3.1
Is this queued for 6.0 ?
> -----Original Message-----
> From: Saurabh Sengar <[email protected]>
> Sent: Wednesday, August 24, 2022 12:21 AM
> To: [email protected]; [email protected]; [email protected]; linux-
> [email protected]; [email protected]; Saurabh Singh Sengar
> <[email protected]>; Michael Kelley (LINUX)
> <[email protected]>; [email protected]
> Subject: [PATCH v2] md : Replace snprintf with scnprintf
>
> 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_*()")
> Reviewed-by: Michael Kelley <[email protected]>
> Acked-by: Guoqing Jiang <[email protected]>
> Signed-off-by: Saurabh Sengar <[email protected]>
> ---
> V2 :
> - Rebase
>
> 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 78addfe..857c493
> 100644
> --- a/drivers/md/raid0.c
> +++ b/drivers/md/raid0.c
> @@ -47,7 +47,7 @@ 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%pg", k?"/":"",
> + len += scnprintf(line+len, 200-len, "%s%pg", k?"/":"",
> conf->devlist[j * raid_disks + k]->bdev);
> pr_debug("md: zone%d=[%s]\n", j, line);
>
> --
> 1.8.3.1
On Mon, Sep 19, 2022 at 9:47 AM Saurabh Singh Sengar
<[email protected]> wrote:
>
> Is this queued for 6.0 ?
This is queued for 6.1.
Thanks,
Song
>
> > -----Original Message-----
> > From: Saurabh Sengar <[email protected]>
> > Sent: Wednesday, August 24, 2022 12:21 AM
> > To: [email protected]; [email protected]; [email protected]; linux-
> > [email protected]; [email protected]; Saurabh Singh Sengar
> > <[email protected]>; Michael Kelley (LINUX)
> > <[email protected]>; [email protected]
> > Subject: [PATCH v2] md : Replace snprintf with scnprintf
> >
> > 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_*()")
> > Reviewed-by: Michael Kelley <[email protected]>
> > Acked-by: Guoqing Jiang <[email protected]>
> > Signed-off-by: Saurabh Sengar <[email protected]>
> > ---
> > V2 :
> > - Rebase
> >
> > 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 78addfe..857c493
> > 100644
> > --- a/drivers/md/raid0.c
> > +++ b/drivers/md/raid0.c
> > @@ -47,7 +47,7 @@ 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%pg", k?"/":"",
> > + len += scnprintf(line+len, 200-len, "%s%pg", k?"/":"",
> > conf->devlist[j * raid_disks + k]->bdev);
> > pr_debug("md: zone%d=[%s]\n", j, line);
> >
> > --
> > 1.8.3.1
>