From 0631b6beaed60ba118b0b027c0f8d35397bf5df0 Mon Sep 17 00:00:00 2001 From: Keno Fischer Date: Thu, 30 Sep 2021 03:51:23 -0400 Subject: [PATCH] Fix out of bounds read in slarrv This was originally reported as https://github.com/JuliaLang/julia/issues/42415. I've tracked this down to an our of bounds read on the following line: https://github.com/Reference-LAPACK/lapack/blob/44ecb6a5ff821b1cbb39f8cc2166cb098e060b4d/SRC/slarrv.f#L423 In the crashing example, `M` is `0`, causing `slarrv` to read uninitialized memory from the work array. I believe the `0` for `M` is correct and indeed, the documentation above supports that `M` may be zero: https://github.com/Reference-LAPACK/lapack/blob/44ecb6a5ff821b1cbb39f8cc2166cb098e060b4d/SRC/slarrv.f#L113-L116 I believe it may be sufficient to early-out this function as suggested in this PR. However, I have limited context for the full routine here, so I would appreciate a sanity check. [Retrieved from: https://github.com/Reference-LAPACK/lapack/commit/38f3eeee3108b18158409ca2a100e6fe03754781] Signed-off-by: Fabrice Fontaine --- SRC/clarrv.f | 2 +- SRC/dlarrv.f | 2 +- SRC/slarrv.f | 2 +- SRC/zlarrv.f | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/SRC/clarrv.f b/SRC/clarrv.f index 1f09e4da6..42f710757 100644 --- a/SRC/clarrv.f +++ b/SRC/clarrv.f @@ -348,7 +348,7 @@ SUBROUTINE CLARRV( N, VL, VU, D, L, PIVMIN, * * Quick return if possible * - IF( N.LE.0 ) THEN + IF( (N.LE.0).OR.(M.LE.0) ) THEN RETURN END IF * diff --git a/SRC/dlarrv.f b/SRC/dlarrv.f index b036c1e66..299430361 100644 --- a/SRC/dlarrv.f +++ b/SRC/dlarrv.f @@ -350,7 +350,7 @@ SUBROUTINE DLARRV( N, VL, VU, D, L, PIVMIN, * * Quick return if possible * - IF( N.LE.0 ) THEN + IF( (N.LE.0).OR.(M.LE.0) ) THEN RETURN END IF * diff --git a/SRC/slarrv.f b/SRC/slarrv.f index 9d72b339a..95f94fd1b 100644 --- a/SRC/slarrv.f +++ b/SRC/slarrv.f @@ -350,7 +350,7 @@ SUBROUTINE SLARRV( N, VL, VU, D, L, PIVMIN, * * Quick return if possible * - IF( N.LE.0 ) THEN + IF( (N.LE.0).OR.(M.LE.0) ) THEN RETURN END IF * diff --git a/SRC/zlarrv.f b/SRC/zlarrv.f index 51ec558f5..e4be63e0d 100644 --- a/SRC/zlarrv.f +++ b/SRC/zlarrv.f @@ -348,7 +348,7 @@ SUBROUTINE ZLARRV( N, VL, VU, D, L, PIVMIN, * * Quick return if possible * - IF( N.LE.0 ) THEN + IF( (N.LE.0).OR.(M.LE.0) ) THEN RETURN END IF *