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author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2014-11-30 13:51:03 +0100 |
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committer | Brian Norris <computersforpeace@gmail.com> | 2014-12-12 19:12:16 -0800 |
commit | 92b633a8a482c4bc1ff3b7cffdcace7836861554 (patch) | |
tree | 7b64321201ddde6d9cd049851039156d3221a39b /drivers/mtd/maps | |
parent | 58c81957b7d284c57a9fc1b815c77155ef744ea5 (diff) | |
download | lwn-92b633a8a482c4bc1ff3b7cffdcace7836861554.tar.gz lwn-92b633a8a482c4bc1ff3b7cffdcace7836861554.zip |
mtd: physmap_of: fix potential NULL dereference
On device remove, when testing the cmtd field of an of_flash
struct to decide whether it is a concatenated device or not,
we get a false positive on cmtd == NULL, and dereference it
subsequently. This may occur if of_flash_remove() is called
from the cleanup path of of_flash_probe().
Instead, test for NULL first, and only then perform the test
for a concatenated device.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/maps')
-rw-r--r-- | drivers/mtd/maps/physmap_of.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c index c1d21cb501ca..e48930424091 100644 --- a/drivers/mtd/maps/physmap_of.c +++ b/drivers/mtd/maps/physmap_of.c @@ -47,14 +47,12 @@ static int of_flash_remove(struct platform_device *dev) return 0; dev_set_drvdata(&dev->dev, NULL); - if (info->cmtd != info->list[0].mtd) { + if (info->cmtd) { mtd_device_unregister(info->cmtd); - mtd_concat_destroy(info->cmtd); + if (info->cmtd != info->list[0].mtd) + mtd_concat_destroy(info->cmtd); } - if (info->cmtd) - mtd_device_unregister(info->cmtd); - for (i = 0; i < info->list_size; i++) { if (info->list[i].mtd) map_destroy(info->list[i].mtd); |