wg302v1_fixup() looks for the ATAG_CMDLINE atag, it doesn't find it and
so it takes the last atag in the list and overwrites non allocated
memory.
The side effects are corrupted vital data and a kernel that doesn't
boot. More details here https://dev.openwrt.org/ticket/18356
The fix appends the fixup to the command line and updates the atag only
when it finds it.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
SVN-Revision: 43320
-+static char wg302v1_mem_fixup[] __initdata = "mem=32M ";
++static char wg302v1_mem_fixup[] __initdata = " mem=32M";
+
+static void __init wg302v1_fixup(struct tag *tags, char **cmdline,
+ struct meminfo *mi)
+{
+ struct tag *t = tags;
+ char *p = *cmdline;
+
+static void __init wg302v1_fixup(struct tag *tags, char **cmdline,
+ struct meminfo *mi)
+{
+ struct tag *t = tags;
+ char *p = *cmdline;
++ size_t fixlen, cmdlen;
+
+ /* Find the end of the tags table, taking note of any cmdline tag. */
+ for (; t->hdr.size; t = tag_next(t)) {
+
+ /* Find the end of the tags table, taking note of any cmdline tag. */
+ for (; t->hdr.size; t = tag_next(t)) {
-+ /* Overwrite the end of the table with a new cmdline tag. */
-+ t->hdr.tag = ATAG_CMDLINE;
-+ t->hdr.size = (sizeof (struct tag_header) +
-+ strlen(wg302v1_mem_fixup) + strlen(p) + 1 + 4) >> 2;
-+ strlcpy(t->u.cmdline.cmdline, wg302v1_mem_fixup, COMMAND_LINE_SIZE);
-+ strlcpy(t->u.cmdline.cmdline + strlen(wg302v1_mem_fixup), p,
-+ COMMAND_LINE_SIZE - strlen(wg302v1_mem_fixup));
++ fixlen = strlen(wg302v1_mem_fixup);
++ cmdlen = strlen(p);
++ if (fixlen + cmdlen >= COMMAND_LINE_SIZE)
++ return;
-+ /* Terminate the table. */
-+ t = tag_next(t);
-+ t->hdr.tag = ATAG_NONE;
-+ t->hdr.size = 0;
++ /* append the fixup to the cmdline */
++ memmove(p + cmdlen, wg302v1_mem_fixup, fixlen + 1);
++
++ /* Adjust the size of the atag if there was one */
++ if (t->hdr.size)
++ t->hdr.size += fixlen;
+}
+
static void __init wg302v1_init(void)
+}
+
static void __init wg302v1_init(void)