diff options
author | Aleksei Vetrov <vvvvvv@google.com> | 2023-11-23 14:51:08 +0000 |
---|---|---|
committer | Gerrit Code Review <noreply-gerritcodereview@google.com> | 2023-11-23 14:51:08 +0000 |
commit | 76a472ca351d67e39910686fef6243064ffc1032 (patch) | |
tree | e75e54eada4a721a2dab5cb7ded84d134925138c | |
parent | 7c7f2af329ae801ce6f71ade19a1744495bff3d6 (diff) | |
parent | f59ea30d157320e1bf003bcfbbfd7b648f195b8e (diff) | |
download | elfutils-76a472ca351d67e39910686fef6243064ffc1032.tar.gz |
Merge changes I55db8ff5,I8d73a876 into main
* changes:
libdwfl: handle duplicate ELFs when reporting archives
libdw: check offset dwarf_formstring in all cases
-rw-r--r-- | libdw/dwarf_formstring.c | 6 | ||||
-rw-r--r-- | libdwfl/dwfl_report_elf.c | 3 | ||||
-rw-r--r-- | patches/libdw-check-offset-dwarf_formstring-in-all-cases.patch | 36 | ||||
-rw-r--r-- | patches/libdwfl-handle-duplicate-ELFs-when-reporting-archive.patch | 56 |
4 files changed, 97 insertions, 4 deletions
diff --git a/libdw/dwarf_formstring.c b/libdw/dwarf_formstring.c index 0ee42411..65f03a5e 100644 --- a/libdw/dwarf_formstring.c +++ b/libdw/dwarf_formstring.c @@ -173,11 +173,11 @@ dwarf_formstring (Dwarf_Attribute *attrp) off = read_4ubyte_unaligned (dbg, datap); else off = read_8ubyte_unaligned (dbg, datap); - - if (off >= data_size) - goto invalid_offset; } + if (off >= data_size) + goto invalid_offset; + return (const char *) data->d_buf + off; } INTDEF(dwarf_formstring) diff --git a/libdwfl/dwfl_report_elf.c b/libdwfl/dwfl_report_elf.c index 581f4079..a76d3681 100644 --- a/libdwfl/dwfl_report_elf.c +++ b/libdwfl/dwfl_report_elf.c @@ -276,10 +276,11 @@ __libdwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name, } else { - elf_end (elf); if (m->main_bias != bias || m->main.vaddr != vaddr || m->main.address_sync != address_sync) goto overlap; + elf_end (m->main.elf); + m->main.elf = elf; } } return m; diff --git a/patches/libdw-check-offset-dwarf_formstring-in-all-cases.patch b/patches/libdw-check-offset-dwarf_formstring-in-all-cases.patch new file mode 100644 index 00000000..7e30d2a3 --- /dev/null +++ b/patches/libdw-check-offset-dwarf_formstring-in-all-cases.patch @@ -0,0 +1,36 @@ +From 1bd9deb9aa19ac2e2fa9665009e0d5924adcf4d3 Mon Sep 17 00:00:00 2001 +From: Aleksei Vetrov <vvvvvv@google.com> +Date: Thu, 16 Nov 2023 21:29:22 +0000 +Subject: [PATCH] libdw: check offset dwarf_formstring in all cases + +This check was initially added to test if offset overflows the safe +prefix where any string will be null-terminated. However the check +was placed in a wrong place and didn't cover all `attrp->form` cases. + + * libdw/dwarf_formstring.c (dwarf_formstring): Move offset check + right before returning the result. + +Signed-off-by: Aleksei Vetrov <vvvvvv@google.com> + +diff --git a/libdw/dwarf_formstring.c b/libdw/dwarf_formstring.c +index 0ee42411..65f03a5e 100644 +--- a/libdw/dwarf_formstring.c ++++ b/libdw/dwarf_formstring.c +@@ -173,11 +173,11 @@ dwarf_formstring (Dwarf_Attribute *attrp) + off = read_4ubyte_unaligned (dbg, datap); + else + off = read_8ubyte_unaligned (dbg, datap); +- +- if (off >= data_size) +- goto invalid_offset; + } + ++ if (off >= data_size) ++ goto invalid_offset; ++ + return (const char *) data->d_buf + off; + } + INTDEF(dwarf_formstring) +-- +2.43.0.rc1.413.gea7ed67945-goog + diff --git a/patches/libdwfl-handle-duplicate-ELFs-when-reporting-archive.patch b/patches/libdwfl-handle-duplicate-ELFs-when-reporting-archive.patch new file mode 100644 index 00000000..021ecdcf --- /dev/null +++ b/patches/libdwfl-handle-duplicate-ELFs-when-reporting-archive.patch @@ -0,0 +1,56 @@ +From 0ab5a3eb4122f36cbaff259e7a0a3f9d014cb6f7 Mon Sep 17 00:00:00 2001 +From: Aleksei Vetrov <vvvvvv@google.com> +Date: Mon, 20 Nov 2023 17:44:47 +0000 +Subject: [PATCH] libdwfl: handle duplicate ELFs when reporting archives + +When archive is processed in process_archive (libdwfl/offline.c), it +creates an Elf object for each archive member. Then in +process_archive_member it calls process_file to create a Dwfl_Module +through __libdwfl_report_elf. + +The ownership of the Elf object is expected to be: + +* either transfered to the Dwfl_Module, if __libdwfl_report_elf returns + not NULL; + +* or handled at the end of process_archive_member by calling elf_end. + +Moreover, Elf object is expected to be alive, if __libdwfl_report_elf +returns not NULL, because at the end of process_archive_member it +advances to the next member through the elf_next call. + +The problem happens when __libdwfl_report_elf encounters Elf with the +same name and content as it seen before. In that case dwfl_report_module +will reuse existing Dwfl_Module object. This leads to a codepath that +calls elf_end on the Elf object, while returning not NULL, breaking the +elf_next call to the next member. + +The fix is to destroy m->main.elf instead and put the new Elf object in +the already existing Dwfl_Module. + + * libdwfl/dwfl_report_elf.c (__libdwfl_report_elf): Replace Elf in + the Dwfl_Module in case of duplicate modules to prolong its + lifetime for subsequent processing. + +Signed-off-by: Aleksei Vetrov <vvvvvv@google.com> + +diff --git a/libdwfl/dwfl_report_elf.c b/libdwfl/dwfl_report_elf.c +index 581f4079..a76d3681 100644 +--- a/libdwfl/dwfl_report_elf.c ++++ b/libdwfl/dwfl_report_elf.c +@@ -276,10 +276,11 @@ __libdwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name, + } + else + { +- elf_end (elf); + if (m->main_bias != bias + || m->main.vaddr != vaddr || m->main.address_sync != address_sync) + goto overlap; ++ elf_end (m->main.elf); ++ m->main.elf = elf; + } + } + return m; +-- +2.43.0.rc1.413.gea7ed67945-goog + |