From f7b39e760d5b9fc1912c71f4e6e4ca5e99992dc3 Mon Sep 17 00:00:00 2001
From: Aravindh Krishnamoorthy <aravindh.krishnamoorthy@fau.de>
Date: Wed, 3 May 2023 09:19:12 +0200
Subject: [PATCH] Ensure length(ipiv)==n before calling LAPACK.getrs! to avoid
 segfaults (#49602)

(cherry picked from commit b66f63c5add314bc345e2a7e1ad775d52ad58065)
---
 stdlib/LinearAlgebra/src/lapack.jl  | 3 +++
 stdlib/LinearAlgebra/test/lapack.jl | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/stdlib/LinearAlgebra/src/lapack.jl b/stdlib/LinearAlgebra/src/lapack.jl
index 9edaf77440750..bef018307fcf7 100644
--- a/stdlib/LinearAlgebra/src/lapack.jl
+++ b/stdlib/LinearAlgebra/src/lapack.jl
@@ -1010,6 +1010,9 @@ for (gels, gesv, getrs, getri, elty) in
             if n != size(B, 1)
                 throw(DimensionMismatch("B has leading dimension $(size(B,1)), but needs $n"))
             end
+            if n != length(ipiv)
+                throw(DimensionMismatch("ipiv has length $(length(ipiv)), but needs to be $n"))
+            end
             nrhs = size(B, 2)
             info = Ref{BlasInt}()
             ccall((@blasfunc($getrs), libblastrampoline), Cvoid,
diff --git a/stdlib/LinearAlgebra/test/lapack.jl b/stdlib/LinearAlgebra/test/lapack.jl
index e0e75f0a88413..f8baceebaff52 100644
--- a/stdlib/LinearAlgebra/test/lapack.jl
+++ b/stdlib/LinearAlgebra/test/lapack.jl
@@ -709,4 +709,13 @@ a = zeros(2,0), zeros(0)
 @test LinearAlgebra.LAPACK.geqrf!(a...) === a
 @test LinearAlgebra.LAPACK.gerqf!(a...) === a
 
+# Issue #49489: https://github.com/JuliaLang/julia/issues/49489
+# Dimension mismatch between A and ipiv causes segfaults
+@testset "issue #49489" begin
+    A = randn(23,23)
+    b = randn(23)
+    ipiv = collect(1:20)
+    @test_throws DimensionMismatch LinearAlgebra.LAPACK.getrs!('N', A, ipiv, b)
+end
+
 end # module TestLAPACK