Adding a fix for hist_lines memory leak and state loss. In current code, we overwrite hist_lines before checking the allocation result. If grub_calloc fails, hist_lines becomes NULL and we loose the reference to the previously allocated hist_lines. With this new change. On failure, hist_lines remains pointing to the old valid memory. No leak, no state corruption.
Along with this, adding a failure check in grub_calloc(). If grub_calloc fails, (e.g., due to memory allocation failure), it returns NULL. Then, passing hist_lines (which would be NULL) to grub_memmove() will result in a null pointer dereference, and can cause an undefined behavior. Signed-off-by: Avnish Chouhan <[email protected]> --- grub-core/normal/cmdline.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/grub-core/normal/cmdline.c b/grub-core/normal/cmdline.c index 9c6d9ad..14a40a4 100644 --- a/grub-core/normal/cmdline.c +++ b/grub-core/normal/cmdline.c @@ -42,7 +42,14 @@ grub_err_t grub_set_history (int newsize) { grub_uint32_t **old_hist_lines = hist_lines; + hist_lines = grub_calloc (newsize, sizeof (grub_uint32_t *)); + if (hist_lines == NULL) + { + /* We need to restore hist_lines to avoid memory leak and state loss */ + hist_lines = old_hist_lines; + return grub_errno; + } /* Copy the old lines into the new buffer. */ if (old_hist_lines) -- 2.47.1 _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
