From: Gabor Juhos Date: Wed, 13 Dec 2017 19:31:50 +0000 (+0100) Subject: ar71xx: fix invalid pointer dereference in c60_nand_scan_fixup() X-Git-Tag: v18.06.0-rc1~1563 X-Git-Url: http://git.openwrt.org/?p=openwrt%2Fopenwrt.git;a=commitdiff_plain;h=2ecc4131077b26ed8b95b88dea870b1f3a9444c2 ar71xx: fix invalid pointer dereference in c60_nand_scan_fixup() Since Linux 4.6, mtd->priv no longer points to the NAND specific structure. Under 4.9 it contains NULL, thus using it to access the fields of the nand_chip structure causes an invalid pointer dereference. Update the code to use the mtd_to_nand() helper under 4.9 to obtain the address of the chip specific data. Compile tested only. Fixes: 7bbf4117c6fe ("ar71xx: Add kernel 4.9 support") Signed-off-by: Gabor Juhos Tested-by: Christian Lamparter --- diff --git a/target/linux/ar71xx/files/arch/mips/ath79/mach-c60.c b/target/linux/ar71xx/files/arch/mips/ath79/mach-c60.c index 7b01af515b..144f5db740 100644 --- a/target/linux/ar71xx/files/arch/mips/ath79/mach-c60.c +++ b/target/linux/ar71xx/files/arch/mips/ath79/mach-c60.c @@ -180,7 +180,11 @@ static const struct mtd_ooblayout_ops c60_nand_ecclayout_ops = { static int c60_nand_scan_fixup(struct mtd_info *mtd) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0) struct nand_chip *chip = mtd->priv; +#else + struct nand_chip *chip = mtd_to_nand(mtd); +#endif chip->ecc.size = 512; chip->ecc.strength = 4;