From 1aa9a04ff687b8d55b0fb68ae2a688c8705665cc Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Fri, 26 Aug 2022 23:15:55 +0200 Subject: [PATCH] Revert "i2c: fix stack buffer overflow vulnerability in i2c md command" This reverts commit 8f8c04bf1ebbd2f72f1643e7ad9617dafa6e5409. The commit is largely wrong and breaks most of i2c command functionality. The problem described in the aforementioned commit commit message is valid, however the commit itself does many more changes unrelated to fixing that one problem it describes. Those extra changes, namely the handling of i2c device address length as unsigned instead of signed integer, breaks the expectation that address length may be negative value. The negative value is used by DM to indicate that address length of device does not change. The actual bug documented in commit 8f8c04bf1ebbd2f72f1643e7ad9617dafa6e5409 can be fixed by extra sanitization in separate patch. Signed-off-by: Marek Vasut Cc: Heiko Schocher Cc: Nicolas Iooss Cc: Simon Glass Cc: Tim Harvey Reviewed-by: Simon Glass --- cmd/i2c.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/cmd/i2c.c b/cmd/i2c.c index bd04b14..9050b2b 100644 --- a/cmd/i2c.c +++ b/cmd/i2c.c @@ -200,10 +200,10 @@ void i2c_init_board(void) * * Returns the address length. */ -static uint get_alen(char *arg, uint default_len) +static uint get_alen(char *arg, int default_len) { - uint j; - uint alen; + int j; + int alen; alen = default_len; for (j = 0; j < 8; j++) { @@ -247,7 +247,7 @@ static int do_i2c_read(struct cmd_tbl *cmdtp, int flag, int argc, { uint chip; uint devaddr, length; - uint alen; + int alen; u_char *memaddr; int ret; #if CONFIG_IS_ENABLED(DM_I2C) @@ -301,7 +301,7 @@ static int do_i2c_write(struct cmd_tbl *cmdtp, int flag, int argc, { uint chip; uint devaddr, length; - uint alen; + int alen; u_char *memaddr; int ret; #if CONFIG_IS_ENABLED(DM_I2C) @@ -469,8 +469,8 @@ static int do_i2c_md(struct cmd_tbl *cmdtp, int flag, int argc, { uint chip; uint addr, length; - uint alen; - uint j, nbytes, linebytes; + int alen; + int j, nbytes, linebytes; int ret; #if CONFIG_IS_ENABLED(DM_I2C) struct udevice *dev; @@ -589,9 +589,9 @@ static int do_i2c_mw(struct cmd_tbl *cmdtp, int flag, int argc, { uint chip; ulong addr; - uint alen; + int alen; uchar byte; - uint count; + int count; int ret; #if CONFIG_IS_ENABLED(DM_I2C) struct udevice *dev; @@ -676,8 +676,8 @@ static int do_i2c_crc(struct cmd_tbl *cmdtp, int flag, int argc, { uint chip; ulong addr; - uint alen; - uint count; + int alen; + int count; uchar byte; ulong crc; ulong err; @@ -985,7 +985,7 @@ static int do_i2c_loop(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) { uint chip; - uint alen; + int alen; uint addr; uint length; u_char bytes[16]; -- 2.7.4