From: Mark Wielaard Date: Thu, 6 Jan 2022 16:35:13 +0000 (+0100) Subject: libdwfl: Handle unaligned Dyns in dwfl_segment_report_module X-Git-Tag: elfutils-0.187~41 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=90b1b14a9a7e659cf5665855ae07da424e5cbd96;p=thirdparty%2Felfutils.git libdwfl: Handle unaligned Dyns 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=28720 Signed-off-by: Mark Wielaard --- diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index f8319f44c..aace969fe 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,8 @@ +2022-01-03 Mark Wielaard + + * dwfl_segment_report_module.c (dwfl_segment_report_module): Copy + dyn_data and set xlatefrom.d_buf to dyns when dyns is not aligned. + 2022-01-03 Mark Wielaard * link_map.c (read_addrs): Fix buffer_available nb overflow. diff --git a/libdwfl/dwfl_segment_report_module.c b/libdwfl/dwfl_segment_report_module.c index 5bef249e4..1461ae26a 100644 --- a/libdwfl/dwfl_segment_report_module.c +++ b/libdwfl/dwfl_segment_report_module.c @@ -844,7 +844,19 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, xlateto.d_buf = dyns; xlateto.d_size = dyn_filesz; + /* dyn_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). */ bool is32 = (ei_class == ELFCLASS32); + size_t dyn_align = (is32 + ? __alignof__ (Elf32_Dyn) + : __alignof__ (Elf64_Dyn)); + if (((uintptr_t) dyn_data & (dyn_align - 1)) != 0) + { + memcpy (dyns, dyn_data, dyn_filesz); + xlatefrom.d_buf = dyns; + } + if ((is32 && elf32_xlatetom (&xlateto, &xlatefrom, ei_data) != NULL) || (!is32 && elf64_xlatetom (&xlateto, &xlatefrom, ei_data) != NULL)) {