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From: "mark at klomp dot org" <sourceware-bugzilla@sourceware.org>
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Subject: [Bug libdw/28720] UBSan: member access within misaligned address
 0x7f6e8d80f142 for type 'struct Elf32_Phdr', which requires 4 byte alignment
Date: Mon, 03 Jan 2022 23:42:20 +0000
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https://sourceware.org/bugzilla/show_bug.cgi?id=3D28720

--- Comment #7 from Mark Wielaard <mark at klomp dot org> ---
(In reply to Evgeny Vereshchagin from comment #5)
> Created attachment 13875 [details]
> File triggering "member access within misaligned address"

Thanks. afl++ also found this (but only after 8 days...)
I pushed:

commit 9f70a762ab88ceebb8a48a7c9c3ce39ff7f205af
Author: Mark Wielaard <mark@klomp.org>
Date:   Fri Dec 24 02:01:32 2021 +0100

    libdwfl: Calculate addr to read by hand in link_map.c read_addrs.

    The gcc undefined sanitizer doesn't like the trick we use to calculate
    the (possibly) unaligned addresses to read. So calculate them by hand
    as unsigned char pointers.

    https://sourceware.org/bugzilla/show_bug.cgi?id=3D28720

    Signed-off-by: Mark Wielaard <mark@klomp.org>

Which should this particular issue.

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