diff options
| author | Mark Wielaard <mark@klomp.org> | 2018-10-14 16:45:48 +0200 |
|---|---|---|
| committer | Mark Wielaard <mark@klomp.org> | 2018-10-20 00:13:09 +0200 |
| commit | 20f9de9b5f704cec55df92406a50bcbcfca96acd (patch) | |
| tree | 5f46e46f7f79cc385454edb73b8eeee48d8bd365 | |
| parent | 2f4a040fab520a97480f6ca6fa9fcef88bc55255 (diff) | |
libdwfl: Sanity check partial core file data reads.
There were two issues when reading note data from a core file.
We didn't check if the data we already had in a buffer was big
enough. And if we did get the data, we should check if we got
everything, or just a part of the data.
https://sourceware.org/bugzilla/show_bug.cgi?id=23752
Signed-off-by: Mark Wielaard <mark@klomp.org>
| -rw-r--r-- | libdwfl/ChangeLog | 7 | ||||
| -rw-r--r-- | libdwfl/dwfl_segment_report_module.c | 13 |
2 files changed, 18 insertions, 2 deletions
diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index c5ea5634..2e7efd45 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,10 @@ +2018-10-14 Mark Wielaard <mark@klomp.org> + + * dwfl_segment_report_module.c (read_portion): Check requested + filesz isn't larger than buffer_available. + (dwfl_segment_report_module): Check data_size vs filesz after + read_portion call. + 2018-10-02 Andreas Schwab <schwab@suse.de> * relocate.c (relocate): Handle ADD/SUB relocations. diff --git a/libdwfl/dwfl_segment_report_module.c b/libdwfl/dwfl_segment_report_module.c index 36e5c823..87498846 100644 --- a/libdwfl/dwfl_segment_report_module.c +++ b/libdwfl/dwfl_segment_report_module.c @@ -1,5 +1,5 @@ /* Sniff out modules from ELF headers visible in memory segments. - Copyright (C) 2008-2012, 2014, 2015 Red Hat, Inc. + Copyright (C) 2008-2012, 2014, 2015, 2018 Red Hat, Inc. This file is part of elfutils. This file is free software; you can redistribute it and/or modify @@ -301,7 +301,10 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, inline bool read_portion (void **data, size_t *data_size, GElf_Addr vaddr, size_t filesz) { - if (vaddr - start + filesz > buffer_available + /* Check whether we will have to read the segment data, or if it + can be returned from the existing buffer. */ + if (filesz > buffer_available + || vaddr - start > buffer_available - filesz /* If we're in string mode, then don't consider the buffer we have sufficient unless it contains the terminator of the string. */ || (filesz == 0 && memchr (vaddr - start + buffer, '\0', @@ -459,6 +462,12 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, if (read_portion (&data, &data_size, vaddr, filesz)) return; + /* data_size will be zero if we got everything from the initial + buffer, otherwise it will be the size of the new buffer that + could be read. */ + if (data_size != 0) + filesz = data_size; + assert (sizeof (Elf32_Nhdr) == sizeof (Elf64_Nhdr)); void *notes; |