github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-24 06:24:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

RDMA/core: Fix potential use after free in ib_destroy_cq_user()

Browse Source 
When accessing a CQ via the netlink path the only synchronization
mechanism for the said CQ is rdma_restrack_get().
Currently, rdma_restrack_del() is invoked at the end of
ib_destroy_cq_user(), which is too late, since by that point
vendor-specific resources associated with the CQ might already be
freed. This can leave a short window where the CQ remains accessible
through restrack, leading to a potential use-after-free.

Fix this by moving the rdma_restrack_begin_del() call to the start of
ib_destroy_cq_user(), ensuring that the CQ is removed from restrack
before its internal resources are released. This guarantees that no new
users hold references to a CQ that is in the process of destruction.

In addition, this change preserves the intended inverted order
between create and destroy routines: resources are added to
restrack at the end of successful creation, and hence shall be removed
from the restrack first thing during the destruction flow, which keeps
the lifecycle management consistent and predictable.

Fixes: 08f294a152 ("RDMA/core: Add resource tracking for create and destroy CQs")
Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
Link: https://patch.msgid.link/20260713-restrack-uaf-fix-resub-v2-3-bbe8bb270d51@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Patrisious Haddad 2026-07-13 18:38:02 +03:00 committed by Leon Romanovsky
parent 709ba0e531
commit 3481bec4df
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/infiniband/core/verbs.c
View File

@ -2247,11 +2247,15 @@ int ib_destroy_cq_user(struct ib_cq *cq, struct ib_udata *udata)
if (atomic_read(&cq->usecnt))
return -EBUSY;
ret = cq->device->ops.destroy_cq(cq, udata);
if (ret)
return ret;
rdma_restrack_begin_del(&cq->res);
rdma_restrack_del(&cq->res);
ret = cq->device->ops.destroy_cq(cq, udata);
if (ret) {
rdma_restrack_abort_del(&cq->res);
return ret;
}
rdma_restrack_commit_del(&cq->res);
kfree(cq);
return ret;
}