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authorLv Yunlong <lyl2019@mail.ustc.edu.cn>2021-04-26 04:16:47 +0300
committerJason Gunthorpe <jgg@nvidia.com>2021-04-27 21:19:21 +0300
commit3093ee182f01689b89e9f8797b321603e5de4f63 (patch)
treeae8990dd3fe23814c0ef425b1dea8e21b89abeb4 /drivers/infiniband
parent2d085ee1728e6ed52f63f221a8ac44cb744e7a84 (diff)
downloadlinux-3093ee182f01689b89e9f8797b321603e5de4f63.tar.xz
RDMA/siw: Fix a use after free in siw_alloc_mr
Our code analyzer reported a UAF. In siw_alloc_mr(), it calls siw_mr_add_mem(mr,..). In the implementation of siw_mr_add_mem(), mem is assigned to mr->mem and then mem is freed via kfree(mem) if xa_alloc_cyclic() failed. Here, mr->mem still point to a freed object. After, the execution continue up to the err_out branch of siw_alloc_mr, and the freed mr->mem is used in siw_mr_drop_mem(mr). My patch moves "mr->mem = mem" behind the if (xa_alloc_cyclic(..)<0) {} section, to avoid the uaf. Fixes: 2251334dcac9 ("rdma/siw: application buffer management") Link: https://lore.kernel.org/r/20210426011647.3561-1-lyl2019@mail.ustc.edu.cn Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> Reviewed-by: Bernard Metzler <bmt@zurich.ihm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/sw/siw/siw_mem.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c
index 34a910cf0edb..61c17db70d65 100644
--- a/drivers/infiniband/sw/siw/siw_mem.c
+++ b/drivers/infiniband/sw/siw/siw_mem.c
@@ -106,8 +106,6 @@ int siw_mr_add_mem(struct siw_mr *mr, struct ib_pd *pd, void *mem_obj,
mem->perms = rights & IWARP_ACCESS_MASK;
kref_init(&mem->ref);
- mr->mem = mem;
-
get_random_bytes(&next, 4);
next &= 0x00ffffff;
@@ -116,6 +114,8 @@ int siw_mr_add_mem(struct siw_mr *mr, struct ib_pd *pd, void *mem_obj,
kfree(mem);
return -ENOMEM;
}
+
+ mr->mem = mem;
/* Set the STag index part */
mem->stag = id << 8;
mr->base_mr.lkey = mr->base_mr.rkey = mem->stag;