diff options
| author | Yanjiang Jin <yanjiang.jin@hxt-semitech.com> | 2018-09-29 12:06:55 +0300 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2018-10-01 14:46:13 +0300 |
| commit | 54a58185bfafb5af5045fb8388c45daa373f90f3 (patch) | |
| tree | 1b01b7f08ddac944ac700d398d0ae7a0f018e9bd /drivers/pinctrl | |
| parent | 18887f31df122951b73be098e416fc871f426b0b (diff) | |
| download | linux-54a58185bfafb5af5045fb8388c45daa373f90f3.tar.xz | |
pinctrl: core: make sure strcmp() doesn't get a null parameter
Some drivers, for example, QCOM's qdf2xxx, set groups[gpio].name only
when gpio is valid, and leave invalid gpio names as null.
If we want to access the sys node "pinconf-groups",
pinctrl_get_group_selector() -> get_group_name() may return a null
pointer if group_selector is invalid, then the below Kernel panic
would happen since strcmp() uses this null pointer to do comparison.
Unable to handle kernel NULL pointer dereference at ss 00000000
el:Internal error: Oops: 9600000[ 143.080279]
SMP
CPU: 19 PID: 2493 Comm: read_all Tainted: G O
.aarch64 #1
Hardware name: HXT Semiconductor HXT REP-2 System
PC is at strcmp+0x18/0x154
LR is at pinctrl_get_group_selector+0x6c/0xe8
Process read_all (pid: 2493, stack limit =
Call trace:
Exception stack
strcmp+0x18/0x154
pin_config_group_get+0x64/0xd8
pinconf_generic_dump_one+0xd8/0x1c0
pinconf_generic_dump_pins+0x94/0xc8
pinconf_groups_show+0xb4/0x104
seq_read+0x178/0x464
full_proxy_read+0x6c/0xac
__vfs_read+0x58/0x178
vfs_read+0x94/0x164
SyS_read+0x60/0xc0
__sys_trace_return+0x0/0x4
--[ end trace]--
Kernel panic - not syncing: Fatal exception
Signed-off-by: Yanjiang Jin <yanjiang.jin@hxt-semitech.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl')
| -rw-r--r-- | drivers/pinctrl/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index a3dd777e3ce8..c6ff4d5fa482 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -627,7 +627,7 @@ static int pinctrl_generic_group_name_to_selector(struct pinctrl_dev *pctldev, while (selector < ngroups) { const char *gname = ops->get_group_name(pctldev, selector); - if (!strcmp(function, gname)) + if (gname && !strcmp(function, gname)) return selector; selector++; @@ -743,7 +743,7 @@ int pinctrl_get_group_selector(struct pinctrl_dev *pctldev, while (group_selector < ngroups) { const char *gname = pctlops->get_group_name(pctldev, group_selector); - if (!strcmp(gname, pin_group)) { + if (gname && !strcmp(gname, pin_group)) { dev_dbg(pctldev->dev, "found group selector %u for %s\n", group_selector, |