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| author |   Lv Yunlong <lyl2019@mail.ustc.edu.cn> | 2021-04-25 18:16:47 -0700 |
|---|---|---|
| committer |   Jason Gunthorpe <jgg@nvidia.com> | 2021-04-27 15:19:21 -0300 |
| commit | 3093ee182f01689b89e9f8797b321603e5de4f63 (patch) | |
| tree | ae8990dd3fe23814c0ef425b1dea8e21b89abeb4 /drivers/infiniband/sw/siw | |
| parent | IB/hfi1: Remove redundant variable rcd (diff) | |
| download | linux-dev-3093ee182f01689b89e9f8797b321603e5de4f63.tar.xz linux-dev-3093ee182f01689b89e9f8797b321603e5de4f63.zip | |
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/sw/siw')
| -rw-r--r-- | drivers/infiniband/sw/siw/siw_mem.c | 4 |
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; |