On Wed, 2017-10-04 at 20:55 +0200, Mark Wielaard wrote: > The first issue is indeed that almost anything that goes wrong when > setting up the initial Elf handle ends up being described as > ELF_E_INVALID_FILE. Which is not always the correct error code. So I > introduced ELF_E_INVALID_ELF which indicates it is bad ELF data being > encountered and not just the inability to read the data from the file > descriptor. Also in a couple of cases we didn't explicitly set the > libelf errno to indicate what really went wrong. I made sure we > always > do now. > > libelf: Add ELF_E_INVALID_ELF error value. > > [...] > > But while auditing this code it is clear we go out of our way to get > the section (count) making sure we don't touch any bad data. If there > is a change we might read anything bad from the (mmapped) file then > we > explicitly set the elf->state.elf[64|32].scns.cnt to zero. Which is > respected throughout libelf whenever we try to touch section headers. > Except... during the initial read we double check e_shoff is sane and > error out early. Even though the code right below it explicitly > doesn't > use it when scncnt is zero. So we can fix this sanity check. > > libelf: Don't error out when sanity checking e_shoff if scncnt is > zero.
I pushed both these commits to master now. Cheers, Mark
