On Thu, Nov 18, 2021 at 07:44:50PM +0000, Matthias Maennich via Elfutils-devel wrote: > dwfl_linux_kernel_report_modules_ has an outstanding ancient bug when > reading kernel module information from a modules list file. The target > buffer for the module name was sized too small to hold potential values. > Fix that by increasing the value to account for the null termination. > > In practice, this unlikely ever happened, but it now got diagnosed by > LLVM as part of a stricter -Wfortify-source implementation [1]: > > libdwfl/linux-kernel-modules.c:1019:7: error: 'sscanf' may overflow; > destination buffer in argument 3 has size 128, but the corresponding > specifier may require size 129 [-Werror,-Wfortify-source] > modname, &modsz, &modaddr) == 3) > > [1] > https://github.com/llvm/llvm-project/commit/2db66f8d48beeea835cb9a6940e25bc04ab5d941 > > Suggested-by: Paul Pluzhnikov <ppluzhni...@google.com> > Signed-off-by: Matthias Maennich <maenn...@google.com> > Change-Id: I97b4fcb536273e5ccc4e37b0b9f0f8ffb7487909 > --- > libdwfl/linux-kernel-modules.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/libdwfl/linux-kernel-modules.c b/libdwfl/linux-kernel-modules.c > index c0f8dfa4aef2..58c0c417a597 100644 > --- a/libdwfl/linux-kernel-modules.c > +++ b/libdwfl/linux-kernel-modules.c > @@ -1008,7 +1008,7 @@ dwfl_linux_kernel_report_modules (Dwfl *dwfl) > int result = 0; > Dwarf_Addr modaddr; > unsigned long int modsz; > - char modname[128]; > + char modname[128+1]; > char *line = NULL; > size_t linesz = 0; > /* We can't just use fscanf here because it's not easy to distinguish \n
LGTM, thanks. -- ldv
