Commit ed65a4dc authored by Leon Romanovsky's avatar Leon Romanovsky Committed by Jason Gunthorpe

RDMA/ucma: Fix use-after-free access in ucma_close

The error in ucma_create_id() left ctx in the list of contexts belong
to ucma file descriptor. The attempt to close this file descriptor causes
to use-after-free accesses while iterating over such list.

Fixes: 75216638 ("RDMA/cma: Export rdma cm interface to userspace")
Reported-by: <syzbot+dcfd344365a56fbebd0f@syzkaller.appspotmail.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Reviewed-by: default avatarSean Hefty <sean.hefty@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 2975d5de
...@@ -497,6 +497,9 @@ static ssize_t ucma_create_id(struct ucma_file *file, const char __user *inbuf, ...@@ -497,6 +497,9 @@ static ssize_t ucma_create_id(struct ucma_file *file, const char __user *inbuf,
mutex_lock(&mut); mutex_lock(&mut);
idr_remove(&ctx_idr, ctx->id); idr_remove(&ctx_idr, ctx->id);
mutex_unlock(&mut); mutex_unlock(&mut);
mutex_lock(&file->mut);
list_del(&ctx->list);
mutex_unlock(&file->mut);
kfree(ctx); kfree(ctx);
return ret; return ret;
} }
......
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