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Fix owner leakage on partial chown in overlay #198

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Merged
jserv merged 1 commit into from
Jul 14, 2026
+9 −5
Merged

Fix owner leakage on partial chown in overlay #198

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14 changes: 9 additions & 5 deletions src/syscall/chown-overlay.c
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Original file line number Diff line number Diff line change
Expand Up @@ -117,8 +117,8 @@ int chown_overlay_set(uint64_t dev,
}
e->dev = dev;
e->ino = ino;
e->uid = cur_uid;
e->gid = cur_gid;
e->uid = (uint32_t) -1;
e->gid = (uint32_t) -1;
unsigned int idx = bucket_index(dev, ino);
e->next = buckets[idx];
buckets[idx] = e;
Expand All @@ -131,7 +131,9 @@ int chown_overlay_set(uint64_t dev,
if (new_group != (uint32_t) -1)
e->gid = new_group;

if (e->uid == cur_uid && e->gid == cur_gid)
uint32_t effective_uid = e->uid == (uint32_t) -1 ? cur_uid : e->uid;
uint32_t effective_gid = e->gid == (uint32_t) -1 ? cur_gid : e->gid;
if (effective_uid == cur_uid && effective_gid == cur_gid)
remove_locked(dev, ino);

out:
Expand Down Expand Up @@ -164,8 +166,10 @@ void chown_overlay_apply(struct stat *st)
overlay_entry_t *e =
find_locked((uint64_t) st->st_dev, (uint64_t) st->st_ino);
if (e) {
st->st_uid = e->uid;
st->st_gid = e->gid;
if (e->uid != (uint32_t) -1)
st->st_uid = e->uid;
if (e->gid != (uint32_t) -1)
st->st_gid = e->gid;
}

pthread_rwlock_unlock(&overlay_lock);
Expand Down
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