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| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-12-31 02:49:36 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-12-31 02:49:36 +0300 |
| commit | bba3d2daa8a9bc888902275401f15ef48fcdd378 (patch) | |
| tree | 82fc0c9b852be399200d374ed3eb0f91ce9811fe | |
| parent | e01b5781958de08942af341ce26768d5e0fbcdf5 (diff) | |
| download | linux-bba3d2daa8a9bc888902275401f15ef48fcdd378.tar.xz | |
rtc: nvmem: fix possible use after free
In cas of probe failure, devres may free the memory allocated for
rtc->nvram before devm_rtc_release_device() is called. This leads to
rtc_nvram_unregister using it after being freed which may lead to a crash.
This has been shown to happen after commit 461e557b9727 ("rtc: nvmem: use
devm_nvmem_register()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/rtc/nvmem.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/rtc/nvmem.c b/drivers/rtc/nvmem.c index ebdfe8e3a1a0..dce518d5e50e 100644 --- a/drivers/rtc/nvmem.c +++ b/drivers/rtc/nvmem.c @@ -12,6 +12,7 @@ #include <linux/types.h> #include <linux/nvmem-consumer.h> #include <linux/rtc.h> +#include <linux/slab.h> #include <linux/sysfs.h> /* @@ -45,9 +46,7 @@ static int rtc_nvram_register(struct rtc_device *rtc, { int err; - rtc->nvram = devm_kzalloc(rtc->dev.parent, - sizeof(struct bin_attribute), - GFP_KERNEL); + rtc->nvram = kzalloc(sizeof(struct bin_attribute), GFP_KERNEL); if (!rtc->nvram) return -ENOMEM; @@ -64,7 +63,7 @@ static int rtc_nvram_register(struct rtc_device *rtc, err = sysfs_create_bin_file(&rtc->dev.parent->kobj, rtc->nvram); if (err) { - devm_kfree(rtc->dev.parent, rtc->nvram); + kfree(rtc->nvram); rtc->nvram = NULL; } @@ -74,6 +73,8 @@ static int rtc_nvram_register(struct rtc_device *rtc, static void rtc_nvram_unregister(struct rtc_device *rtc) { sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram); + kfree(rtc->nvram); + rtc->nvram = NULL; } /* |