From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Darren Kenny Date: Thu, 5 Nov 2020 10:57:14 +0000 Subject: [PATCH] gnulib/regexec: Fix possible null-dereference It appears to be possible that the mctx->state_log field may be NULL, and the name of this function, clean_state_log_if_needed(), suggests that it should be checking that it is valid to be cleaned before assuming that it does. Fixes: CID 86720 Signed-off-by: Darren Kenny Reviewed-by: Daniel Kiper --- grub-core/gnulib/regexec.c | 3 +++ conf/Makefile.extra-dist | 1 + grub-core/gnulib-fix-regexec-null-deref.patch | 12 ++++++++++++ 3 files changed, 16 insertions(+) create mode 100644 grub-core/gnulib-fix-regexec-null-deref.patch diff --git a/grub-core/gnulib/regexec.c b/grub-core/gnulib/regexec.c index fdc178e07a4..1e4cb2df4e3 100644 --- a/grub-core/gnulib/regexec.c +++ b/grub-core/gnulib/regexec.c @@ -1754,6 +1754,9 @@ clean_state_log_if_needed (re_match_context_t *mctx, Idx next_state_log_idx) { Idx top = mctx->state_log_top; + if (mctx->state_log == NULL) + return REG_NOERROR; + if ((next_state_log_idx >= mctx->input.bufs_len && mctx->input.bufs_len < mctx->input.len) || (next_state_log_idx >= mctx->input.valid_len diff --git a/conf/Makefile.extra-dist b/conf/Makefile.extra-dist index c3506afe792..60d9f564236 100644 --- a/conf/Makefile.extra-dist +++ b/conf/Makefile.extra-dist @@ -28,6 +28,7 @@ EXTRA_DIST += grub-core/genemuinitheader.sh EXTRA_DIST += grub-core/gnulib-fix-null-deref.diff EXTRA_DIST += grub-core/gnulib-fix-null-state-deref.patch +EXTRA_DIST += grub-core/gnulib-fix-regexec-null-deref.patch EXTRA_DIST += grub-core/gnulib-fix-uninit-structure.patch EXTRA_DIST += grub-core/gnulib-fix-unused-value.patch EXTRA_DIST += grub-core/gnulib-fix-width.diff diff --git a/grub-core/gnulib-fix-regexec-null-deref.patch b/grub-core/gnulib-fix-regexec-null-deref.patch new file mode 100644 index 00000000000..db6dac9c9e3 --- /dev/null +++ b/grub-core/gnulib-fix-regexec-null-deref.patch @@ -0,0 +1,12 @@ +--- a/lib/regexec.c 2020-10-21 14:25:35.310195912 +0000 ++++ b/lib/regexec.c 2020-11-05 10:55:09.621542984 +0000 +@@ -1692,6 +1692,9 @@ + { + Idx top = mctx->state_log_top; + ++ if (mctx->state_log == NULL) ++ return REG_NOERROR; ++ + if ((next_state_log_idx >= mctx->input.bufs_len + && mctx->input.bufs_len < mctx->input.len) + || (next_state_log_idx >= mctx->input.valid_len