From: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de> stable inclusion from stable-v5.10.258 commit 6e70ef53e818c53eab28d7b0026b7fd03dddaba5 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15657 CVE: CVE-2026-52955 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 4c79fc2d598694bda845b46229c9d48b65042970 upstream. A message of type CEPH_MSG_OSD_MAP containing a crush map with at least one bucket has two fields holding the bucket algorithm. If the values in these two fields differ, an out-of-bounds access can occur. This is the case because the first algorithm field (alg) is used to allocate the correct amount of memory for a bucket of this type, while the second algorithm field inside the bucket (b->alg) is used in the subsequent processing. This patch fixes the issue by adding a check that compares alg and b->alg and aborts the processing in case they differ. Furthermore, b->alg is set to 0 in this case, because the destruction of the crush map also uses this field to determine the bucket type, which can again result in an out-of-bounds access when trying to free the memory pointed to by the fields of the bucket. To correctly free the memory allocated for the bucket in such a case, the corresponding call to kfree is moved from the algorithm-specific crush_destroy_bucket functions to the generic crush_destroy_bucket(). Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ze Zuo <zuoze1@huawei.com> --- net/ceph/crush/crush.c | 6 +----- net/ceph/osdmap.c | 4 ++++ 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/net/ceph/crush/crush.c b/net/ceph/crush/crush.c index 254ded0b05f6..521aec1d5fc0 100644 --- a/net/ceph/crush/crush.c +++ b/net/ceph/crush/crush.c @@ -47,7 +47,6 @@ int crush_get_bucket_item_weight(const struct crush_bucket *b, int p) void crush_destroy_bucket_uniform(struct crush_bucket_uniform *b) { kfree(b->h.items); - kfree(b); } void crush_destroy_bucket_list(struct crush_bucket_list *b) @@ -55,14 +54,12 @@ void crush_destroy_bucket_list(struct crush_bucket_list *b) kfree(b->item_weights); kfree(b->sum_weights); kfree(b->h.items); - kfree(b); } void crush_destroy_bucket_tree(struct crush_bucket_tree *b) { kfree(b->h.items); kfree(b->node_weights); - kfree(b); } void crush_destroy_bucket_straw(struct crush_bucket_straw *b) @@ -70,14 +67,12 @@ void crush_destroy_bucket_straw(struct crush_bucket_straw *b) kfree(b->straws); kfree(b->item_weights); kfree(b->h.items); - kfree(b); } void crush_destroy_bucket_straw2(struct crush_bucket_straw2 *b) { kfree(b->item_weights); kfree(b->h.items); - kfree(b); } void crush_destroy_bucket(struct crush_bucket *b) @@ -99,6 +94,7 @@ void crush_destroy_bucket(struct crush_bucket *b) crush_destroy_bucket_straw2((struct crush_bucket_straw2 *)b); break; } + kfree(b); } /** diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index fe796775e3e9..62cfeb337b8a 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -497,6 +497,10 @@ static struct crush_map *crush_decode(void *pbyval, void *end) b->id = ceph_decode_32(p); b->type = ceph_decode_16(p); b->alg = ceph_decode_8(p); + if (b->alg != alg) { + b->alg = 0; + goto bad; + } b->hash = ceph_decode_8(p); b->weight = ceph_decode_32(p); b->size = ceph_decode_32(p); -- 2.25.1