diff options
Diffstat (limited to 'backport-CVE-2021-33294-readelf-Sanity-check-verneed-and-verdef-offsets-in-h.patch')
| -rw-r--r-- | backport-CVE-2021-33294-readelf-Sanity-check-verneed-and-verdef-offsets-in-h.patch | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/backport-CVE-2021-33294-readelf-Sanity-check-verneed-and-verdef-offsets-in-h.patch b/backport-CVE-2021-33294-readelf-Sanity-check-verneed-and-verdef-offsets-in-h.patch new file mode 100644 index 0000000..f14556e --- /dev/null +++ b/backport-CVE-2021-33294-readelf-Sanity-check-verneed-and-verdef-offsets-in-h.patch @@ -0,0 +1,55 @@ +From 480b6fa3662ba8ffeee274bf0d37423413c01e55 Mon Sep 17 00:00:00 2001 +From: Mark Wielaard <mark@klomp.org> +Date: Wed, 3 Mar 2021 21:40:53 +0100 +Subject: [PATCH] readelf: Sanity check verneed and verdef offsets in + handle_symtab. + +We are going through vna_next, vn_next and vd_next in a while loop. +Make sure that all offsets are sane. We don't want things to wrap +around so we go in cycles. + +https://sourceware.org/bugzilla/show_bug.cgi?id=27501 + +Signed-off-by: Mark Wielaard <mark@klomp.org> +--- + src/readelf.c | 10 +++++++++- + 1 files changed, 9 insertions(+), 1 deletion(-) + +diff --git a/src/readelf.c b/src/readelf.c +index 715af3b3..b9740455 100644 +--- a/src/readelf.c ++++ b/src/readelf.c +@@ -2554,7 +2554,9 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr) + &vernaux_mem); + while (vernaux != NULL + && vernaux->vna_other != *versym +- && vernaux->vna_next != 0) ++ && vernaux->vna_next != 0 ++ && (verneed_data->d_size - vna_offset ++ >= vernaux->vna_next)) + { + /* Update the offset. */ + vna_offset += vernaux->vna_next; +@@ -2571,6 +2573,9 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr) + /* Found it. */ + break; + ++ if (verneed_data->d_size - vn_offset < verneed->vn_next) ++ break; ++ + vn_offset += verneed->vn_next; + verneed = (verneed->vn_next == 0 + ? NULL +@@ -2606,6 +2611,9 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr) + /* Found the definition. */ + break; + ++ if (verdef_data->d_size - vd_offset < verdef->vd_next) ++ break; ++ + vd_offset += verdef->vd_next; + verdef = (verdef->vd_next == 0 + ? NULL +-- +2.27.0 + |