| Message ID | 20220614173352.GA588327@ubuntu |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iwlwifi: pcie: Fixed integer overflow in iwl_write_to_user_buf | expand |
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index bd50f52a1aad..fded5d305b11 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c @@ -2854,7 +2854,7 @@ 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)
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@gmail.com> --- drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)