From 8f8c78cc885d83f999f952dfaa2c2e4595b38f83 Mon Sep 17 00:00:00 2001 From: Mark Wielaard Date: Mon, 20 Dec 2021 01:39:21 +0100 Subject: [PATCH] libdwfl: Handle unaligned Nhdr in dwfl_segment_report_module The xlate functions only handle correctly aligned buffers. But they do handle src == dest. So if the source buffer isn't aligned correctly just copy it first into the destination (which is already correctly aligned). https://sourceware.org/bugzilla/show_bug.cgi?id=28715 Signed-off-by: Mark Wielaard --- libdwfl/ChangeLog | 5 +++++ libdwfl/dwfl_segment_report_module.c | 12 ++++++++++++ 2 files changed, 17 insertions(+) diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index ac0fbe0f7..6015f6b7e 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,8 @@ +2021-12-19 Mark Wielaard + + * dwfl_segment_report_module.c (dwfl_segment_report_module): Copy + data and set xlatefrom.d_buf to notes when data is not aligned. + 2021-12-19 Mark Wielaard * dwfl_segment_report_module.c (dwfl_segment_report_module): Copy diff --git a/libdwfl/dwfl_segment_report_module.c b/libdwfl/dwfl_segment_report_module.c index de190e906..72c850706 100644 --- a/libdwfl/dwfl_segment_report_module.c +++ b/libdwfl/dwfl_segment_report_module.c @@ -573,6 +573,18 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, xlatefrom.d_size = filesz; xlateto.d_buf = notes; xlateto.d_size = filesz; + + /* data may be unaligned, in which case xlatetom would not work. + xlatetom does work when the in and out d_buf are equal (but not + for any other overlap). */ + if ((uintptr_t) data != (align == 8 + ? NOTE_ALIGN8 ((uintptr_t) data) + : NOTE_ALIGN4 ((uintptr_t) data))) + { + memcpy (notes, data, filesz); + xlatefrom.d_buf = notes; + } + if (elf32_xlatetom (&xlateto, &xlatefrom, xencoding) == NULL) { free (notes); -- 2.47.2