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WIP fixing "upx -t" of shared library

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modified:   p_lx_elf.cpp
This commit is contained in:
John Reiser 2022-12-23 11:23:41 -08:00 committed by Markus F.X.J. Oberhumer
parent bb4cbdff44
commit e56b748435
1 changed files with 23 additions and 10 deletions
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33
src/p_lx_elf.cpp
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@ -4921,7 +4921,7 @@ void PackLinuxElf64::un_shlib_1(
)
{
// xct_off [input side] was set by ::unpack when is_shlib
// yct_off [output side]
// yct_off [output side] set here unless is_asl in next 'if' block
unsigned yct_off = xct_off;
// Below xct_off is not compressed (for benefit of rtld.)
@ -4990,7 +4990,6 @@ void PackLinuxElf64::un_shlib_1(
struct b_info b;
} hdr;
fi->readx(&hdr, sizeof(hdr));
fi->seek(-(off_t)sizeof(struct b_info), SEEK_CUR);
if (hdr.l.l_magic != UPX_MAGIC_LE32
|| hdr.l.l_lsize != (unsigned)lsize
|| hdr.p.p_filesize != ph.u_file_size) {
@ -4999,18 +4998,32 @@ void PackLinuxElf64::un_shlib_1(
ph.c_len = get_te32(&hdr.b.sz_cpr);
ph.u_len = get_te32(&hdr.b.sz_unc);
#define MAX_ELF_HDR 1024
if (MAX_ELF_HDR < ph.u_len) {
// FIXME: old-style (upx < 4.0) compresses up to xct_off
throwCantUnpack("ElfXX_Ehdr corrupted");
}
fi->readx(ibuf, ph.c_len);
fi->seek(-(off_t)(sizeof(b_info) + ph.c_len), SEEK_CUR);
decompress(ibuf, o_elfhdrs, false);
Elf64_Ehdr const *const ehdro = (Elf64_Ehdr const *)(void const *)o_elfhdrs;
if (ehdro->e_type !=ehdri.e_type
|| ehdro->e_machine!=ehdri.e_machine
|| ehdro->e_version!=ehdri.e_version
// less strict for EM_PPC64 to workaround earlier bug
|| !( ehdro->e_flags==ehdri.e_flags
|| Elf64_Ehdr::EM_PPC64 == get_te16(&ehdri.e_machine))
|| ehdro->e_ehsize !=ehdri.e_ehsize
// check EI_MAG[0-3], EI_CLASS, EI_DATA, EI_VERSION
|| memcmp(ehdro->e_ident, ehdri.e_ident, Elf64_Ehdr::EI_OSABI)) {
throwCantUnpack("ElfXX_Ehdr corrupted");
}
unpackExtent(ph.u_len, fo,
c_adler, u_adler, false, szb_info);
// FIXME: what if no output file? test mode ("-t") or list mode ("-l")
if (fo) {
InputFile u_fi;
// Recover original Elf headers from current output file
u_fi.open(fo->getName(), 0);
u_fi.readx((void *)o_elfhdrs, o_elfhdrs.getSize());
u_fi.close();
// Re-generate unmodified rtld data below xct_off
// FIXME: depends on (yct_off < limit_dynhdr)
unsigned d = yct_off - ph.u_len;
fo->write(&ibuf[ph.u_len], d);
total_out += d;