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| author |   Aharon Landau <aharonl@nvidia.com> | 2021-01-13 14:16:59 +0200 |
|---|---|---|
| committer |   Jason Gunthorpe <jgg@nvidia.com> | 2021-01-14 12:50:17 -0400 |
| commit | b79f2dc5ffe17b03ec8c55f0d63f65e87bcac676 (patch) | |
| tree | 895aa1515365389bda7639cb958c85f55ff739c8 /drivers/infiniband/core/umem.c | |
| parent | RDMA/ocrdma: Fix use after free in ocrdma_dealloc_ucontext_pd() (diff) | |
| download | linux-dev-b79f2dc5ffe17b03ec8c55f0d63f65e87bcac676.tar.xz linux-dev-b79f2dc5ffe17b03ec8c55f0d63f65e87bcac676.zip | |
RDMA/umem: Avoid undefined behavior of rounddown_pow_of_two()
rounddown_pow_of_two() is undefined when the input is 0. Therefore we need
to avoid it in ib_umem_find_best_pgsz and return 0. Otherwise, it could
result in not rejecting an invalid page size which eventually causes a
kernel oops due to the logical inconsistency.
Fixes: 3361c29e9279 ("RDMA/umem: Use simpler logic for ib_umem_find_best_pgsz()")
Link: https://lore.kernel.org/r/20210113121703.559778-2-leon@kernel.org
Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband/core/umem.c')
| -rw-r--r-- | drivers/infiniband/core/umem.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 7ca4112e3e8f..917338db7ac1 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -135,7 +135,7 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem, */ if (mask) pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0); - return rounddown_pow_of_two(pgsz_bitmap); + return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0; } EXPORT_SYMBOL(ib_umem_find_best_pgsz); |