This is a note to let you know that I've just added the patch titled wifi: iwlwifi: pcie: Fix integer overflow in iwl_write_to_user_buf to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-iwlwifi-pcie-fix-integer-overflow-in-iwl_write_.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f6f78cba994d2045889a0165b8d1f68debac7d4e Author: Hyunwoo Kim <imv4bel@xxxxxxxxx> Date: Fri Apr 14 13:11:59 2023 +0300 wifi: iwlwifi: pcie: Fix integer overflow in iwl_write_to_user_buf [ Upstream commit 58d1b717879bfeabe09b35e41ad667c79933eb2e ] An integer overflow occurs in the iwl_write_to_user_buf() function, which is called by the iwl_dbgfs_monitor_data_read() function. static bool iwl_write_to_user_buf(char __user *user_buf, ssize_t count, void *buf, ssize_t *size, ssize_t *bytes_copied) { int buf_size_left = count - *bytes_copied; buf_size_left = buf_size_left - (buf_size_left % sizeof(u32)); if (*size > buf_size_left) *size = buf_size_left; If the user passes a SIZE_MAX value to the "ssize_t count" parameter, the ssize_t count parameter is assigned to "int buf_size_left". Then compare "*size" with "buf_size_left" . Here, "buf_size_left" is a negative number, so "*size" is assigned "buf_size_left" and goes into the third argument of the copy_to_user function, causing a heap overflow. This is not a security vulnerability because iwl_dbgfs_monitor_data_read() is a debugfs operation with 0400 privileges. Signed-off-by: Hyunwoo Kim <imv4bel@xxxxxxxxx> Signed-off-by: Gregory Greenman <gregory.greenman@xxxxxxxxx> Link: https://lore.kernel.org/r/20230414130637.2d80ace81532.Iecfba549e0e0be21bbb0324675392e42e75bd5ad@changeid Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index ee325950de9d2..04e1f3829e96b 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c @@ -2778,7 +2778,7 @@ static bool iwl_write_to_user_buf(char __user *user_buf, ssize_t count, void *buf, ssize_t *size, ssize_t *bytes_copied) { - int buf_size_left = count - *bytes_copied; + ssize_t buf_size_left = count - *bytes_copied; buf_size_left = buf_size_left - (buf_size_left % sizeof(u32)); if (*size > buf_size_left)