i2c: fix stack buffer overflow vulnerability in i2c md command CVE: CVE-2022-34835
Signed-off-by:Minjae Kim <flower...@gmail.com> --- .../u-boot/files/CVE-2022-34835.patch | 124 ++++++++++++++++++ meta/recipes-bsp/u-boot/u-boot_2020.01.bb | 4 + 2 files changed, 128 insertions(+) create mode 100644 meta/recipes-bsp/u-boot/files/CVE-2022-34835.patch diff --git a/meta/recipes-bsp/u-boot/files/CVE-2022-34835.patch b/meta/recipes-bsp/u-boot/files/CVE-2022-34835.patch new file mode 100644 index 0000000000..f1c1a91dcf --- /dev/null +++ b/meta/recipes-bsp/u-boot/files/CVE-2022-34835.patch @@ -0,0 +1,124 @@ +From 19cc75158388ec7e09e0d2bd7a2866d08974d059 Mon Sep 17 00:00:00 2001 +From: Nicolas Iooss <nicolas.iooss+ub...@ledger.fr> +Date: Fri, 10 Jun 2022 14:50:25 +0000 +Subject: [PATCH] i2c: fix stack buffer overflow vulnerability in i2c md + command + +When running "i2c md 0 0 80000100", the function do_i2c_md parses the +length into an unsigned int variable named length. The value is then +moved to a signed variable: + + int nbytes = length; + #define DISP_LINE_LEN 16 + int linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes; + ret = dm_i2c_read(dev, addr, linebuf, linebytes); + +On systems where integers are 32 bits wide, 0x80000100 is a negative +value to "nbytes > DISP_LINE_LEN" is false and linebytes gets assigned +0x80000100 instead of 16. + +The consequence is that the function which reads from the i2c device +(dm_i2c_read or i2c_read) is called with a 16-byte stack buffer to fill +but with a size parameter which is too large. In some cases, this could +trigger a crash. But with some i2c drivers, such as drivers/i2c/nx_i2c.c +(used with "nexell,s5pxx18-i2c" bus), the size is actually truncated to +a 16-bit integer. This is because function i2c_transfer expects an +unsigned short length. In such a case, an attacker who can control the +response of an i2c device can overwrite the return address of a function +and execute arbitrary code through Return-Oriented Programming. + +Fix this issue by using unsigned integers types in do_i2c_md. While at +it, make also alen unsigned, as signed sizes can cause vulnerabilities +when people forgot to check that they can be negative. + +Signed-off-by: Nicolas Iooss <nicolas.iooss+ub...@ledger.fr> +Reviewed-by: Heiko Schocher <h...@denx.de> + +Upstream-Status: Backport [https://github.com/u-boot/u-boot/commit/8f8c04bf1ebbd2f72f1643e7ad9617dafa6e5409] +Signed-off-by:Minjae Kim <flower...@gmail.com> +--- + cmd/i2c.c | 24 ++++++++++++------------ + 1 file changed, 12 insertions(+), 12 deletions(-) + +diff --git a/cmd/i2c.c b/cmd/i2c.c +index 43a76299b3..f239d3f336 100644 +--- a/cmd/i2c.c ++++ b/cmd/i2c.c +@@ -246,10 +246,10 @@ int i2c_set_bus_speed(unsigned int speed) + * + * Returns the address length. + */ +-static uint get_alen(char *arg, int default_len) ++static uint get_alen(char *arg, uint default_len) + { +- int j; +- int alen; ++ uint j; ++ uint alen; + + alen = default_len; + for (j = 0; j < 8; j++) { +@@ -292,7 +292,7 @@ static int do_i2c_read ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv + { + uint chip; + uint devaddr, length; +- int alen; ++ uint alen; + u_char *memaddr; + int ret; + #ifdef CONFIG_DM_I2C +@@ -345,7 +345,7 @@ static int do_i2c_write(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[ + { + uint chip; + uint devaddr, length; +- int alen; ++ uint alen; + u_char *memaddr; + int ret; + #ifdef CONFIG_DM_I2C +@@ -511,8 +511,8 @@ static int do_i2c_md ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[] + { + uint chip; + uint addr, length; +- int alen; +- int j, nbytes, linebytes; ++ uint alen; ++ uint j, nbytes, linebytes; + int ret; + #ifdef CONFIG_DM_I2C + struct udevice *dev; +@@ -630,9 +630,9 @@ static int do_i2c_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[] + { + uint chip; + ulong addr; +- int alen; ++ uint alen; + uchar byte; +- int count; ++ uint count; + int ret; + #ifdef CONFIG_DM_I2C + struct udevice *dev; +@@ -716,8 +716,8 @@ static int do_i2c_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[] + { + uint chip; + ulong addr; +- int alen; +- int count; ++ uint alen; ++ uint count; + uchar byte; + ulong crc; + ulong err; +@@ -1023,7 +1023,7 @@ static int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv + static int do_i2c_loop(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) + { + uint chip; +- int alen; ++ uint alen; + uint addr; + uint length; + u_char bytes[16]; +-- +2.25.1 + diff --git a/meta/recipes-bsp/u-boot/u-boot_2020.01.bb b/meta/recipes-bsp/u-boot/u-boot_2020.01.bb index 02d67c0db2..16e2340bb6 100644 --- a/meta/recipes-bsp/u-boot/u-boot_2020.01.bb +++ b/meta/recipes-bsp/u-boot/u-boot_2020.01.bb @@ -2,3 +2,7 @@ require u-boot-common.inc require u-boot.inc DEPENDS += "bc-native dtc-native" + +SRC_URI_append = " \ + file://CVE-2022-34835.patch \ +" -- 2.25.1
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