aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/s390/cio
diff options
context:
space:
mode:
authorVasily Gorbik <gor@linux.ibm.com>2019-09-17 20:04:04 +0200
committerVasily Gorbik <gor@linux.ibm.com>2019-09-23 23:27:52 +0200
commitea298e6ee8b34b3ed4366be7eb799d0650ebe555 (patch)
tree388d4637693de1cabdb6fd5887a1c0aec7d80cea /drivers/s390/cio
parents390/topology: avoid firing events before kobjs are created (diff)
downloadlinux-dev-ea298e6ee8b34b3ed4366be7eb799d0650ebe555.tar.xz
linux-dev-ea298e6ee8b34b3ed4366be7eb799d0650ebe555.zip
s390/cio: avoid calling strlen on null pointer
Fix the following kasan finding: BUG: KASAN: global-out-of-bounds in ccwgroup_create_dev+0x850/0x1140 Read of size 1 at addr 0000000000000000 by task systemd-udevd.r/561 CPU: 30 PID: 561 Comm: systemd-udevd.r Tainted: G B Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: ([<0000000231b3db7e>] show_stack+0x14e/0x1a8) [<0000000233826410>] dump_stack+0x1d0/0x218 [<000000023216fac4>] print_address_description+0x64/0x380 [<000000023216f5a8>] __kasan_report+0x138/0x168 [<00000002331b8378>] ccwgroup_create_dev+0x850/0x1140 [<00000002332b618a>] group_store+0x3a/0x50 [<00000002323ac706>] kernfs_fop_write+0x246/0x3b8 [<00000002321d409a>] vfs_write+0x132/0x450 [<00000002321d47da>] ksys_write+0x122/0x208 [<0000000233877102>] system_call+0x2a6/0x2c8 Triggered by: openat(AT_FDCWD, "/sys/bus/ccwgroup/drivers/qeth/group", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 16 write(16, "0.0.bd00,0.0.bd01,0.0.bd02", 26) = 26 The problem is that __get_next_id in ccwgroup_create_dev might set "buf" buffer pointer to NULL and explicit check for that is required. Cc: stable@vger.kernel.org Reviewed-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
-rw-r--r--drivers/s390/cio/ccwgroup.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index c522e9313c50..ae66875a934d 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -372,7 +372,7 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv,
goto error;
}
/* Check for trailing stuff. */
- if (i == num_devices && strlen(buf) > 0) {
+ if (i == num_devices && buf && strlen(buf) > 0) {
rc = -EINVAL;
goto error;
}