Commit 0b90dfda authored by Ian Rogers's avatar Ian Rogers Committed by Namhyung Kim

perf maps: Fix use after free in __maps__fixup_overlap_and_insert

In the case 'before' and 'after' are broken out from pos,
maps_by_address may be changed by __maps__insert, as such it needs
re-reading.

Don't ignore the return value from __maps_insert.

Fixes: 659ad349 ("perf maps: Switch from rbtree to lazily sorted array for addresses")
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Reviewed-by: default avatarJames Clark <james.clark@arm.com>
Cc: Steinar H . Gunderson <sesse@google.com>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240521165109.708593-2-irogers@google.com
parent a9700511
......@@ -741,7 +741,6 @@ static unsigned int first_ending_after(struct maps *maps, const struct map *map)
*/
static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new)
{
struct map **maps_by_address;
int err = 0;
FILE *fp = debug_file();
......@@ -749,12 +748,12 @@ static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new)
if (!maps__maps_by_address_sorted(maps))
__maps__sort_by_address(maps);
maps_by_address = maps__maps_by_address(maps);
/*
* Iterate through entries where the end of the existing entry is
* greater-than the new map's start.
*/
for (unsigned int i = first_ending_after(maps, new); i < maps__nr_maps(maps); ) {
struct map **maps_by_address = maps__maps_by_address(maps);
struct map *pos = maps_by_address[i];
struct map *before = NULL, *after = NULL;
......@@ -821,8 +820,10 @@ static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new)
/* Maps are still ordered, go to next one. */
i++;
if (after) {
__maps__insert(maps, after);
err = __maps__insert(maps, after);
map__put(after);
if (err)
goto out_err;
if (!maps__maps_by_address_sorted(maps)) {
/*
* Sorting broken so invariants don't
......@@ -851,7 +852,7 @@ static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new)
check_invariants(maps);
}
/* Add the map. */
__maps__insert(maps, new);
err = __maps__insert(maps, new);
out_err:
return err;
}
......
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