Messages in this thread Patch in this message | | | From | Zheng Wang <> | Subject | [PATCH] lib/mpi: Fix poential NULL pointer dereference in mpi_fdiv_q | Date | Fri, 3 Feb 2023 16:43:02 +0800 |
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in lib/mpi, there is multiple function that not check the return value of mpi_alloc. One case is mpi_fdiv_q, if tmp == NULL, tmp->nlimbs in mpi_fdiv_qr will cause NULL pointer dereference. As the code is too much, here I only fix one of them. Other function like mpi_barrett_init mpi_copy mpi_alloc_like mpi_set mpi_set_ui mpi_alloc_set_ui has the same problem.
Please let me know if there is a better way to fix the problem.
Note that, as a bug found by static analysis, it can be a false positive or hard to trigger.
Fixes: a8ea8bdd9df9 ("lib/mpi: Extend the MPI library") Signed-off-by: Zheng Wang <zyytlz.wz@163.com> --- lib/mpi/mpi-div.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c index 45beab8b9e9e..e8642265d7d4 100644 --- a/lib/mpi/mpi-div.c +++ b/lib/mpi/mpi-div.c @@ -43,7 +43,8 @@ void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor) void mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor) { MPI tmp = mpi_alloc(mpi_get_nlimbs(quot)); - mpi_fdiv_qr(quot, tmp, dividend, divisor); + if (tmp) + mpi_fdiv_qr(quot, tmp, dividend, divisor); mpi_free(tmp); } -- 2.25.1
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