05.10.2024 19:48, Richard Henderson wrote:
Comparing a string of 4 bytes only works in little-endian.
Adjust bulk bswap to only apply to the note payload.
Perform swapping of the note header manually; the magic
is defined so that it does not need a runtime swap.
I think this is more confusing than my version, but should do the
trick too.
I wasn't sure for my patch because I missed the
for (int i = 0; i < n / 4; i++) { bswap32s() }
loop, - now I see where it gets performs the conversion, and see why my
patch works (and why it should work too) :)
Either way,
Reviewed-by: Michael Tokarev <m...@tls.msk.ru>
Also noted for qemu-stable.
Thanks,
/mjt
Fixes: 83f990eb5adb ("linux-user/elfload: Parse NT_GNU_PROPERTY_TYPE_0 notes")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2596
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/elfload.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 0678c9d506..52c88a68a9 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -3121,11 +3121,11 @@ static bool parse_elf_properties(const ImageSource *src,
}
/*
- * The contents of a valid PT_GNU_PROPERTY is a sequence
- * of uint32_t -- swap them all now.
+ * The contents of a valid PT_GNU_PROPERTY is a sequence of uint32_t.
+ * Swap most of them now, beyond the header and namesz.
*/
#ifdef BSWAP_NEEDED
- for (int i = 0; i < n / 4; i++) {
+ for (int i = 4; i < n / 4; i++) {
bswap32s(note.data + i);
}
#endif
@@ -3135,15 +3135,15 @@ static bool parse_elf_properties(const ImageSource *src,
* immediately follows nhdr and is thus at the 4th word. Further, all
* of the inputs to the kernel's round_up are multiples of 4.
*/
- if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 ||
- note.nhdr.n_namesz != NOTE_NAME_SZ ||
+ if (tswap32(note.nhdr.n_type) != NT_GNU_PROPERTY_TYPE_0 ||
+ tswap32(note.nhdr.n_namesz) != NOTE_NAME_SZ ||
note.data[3] != GNU0_MAGIC) {
error_setg(errp, "Invalid note in PT_GNU_PROPERTY");
return false;
}
off = sizeof(note.nhdr) + NOTE_NAME_SZ;
- datasz = note.nhdr.n_descsz + off;
+ datasz = tswap32(note.nhdr.n_descsz) + off;
if (datasz > n) {
error_setg(errp, "Invalid note size in PT_GNU_PROPERTY");
return false;
--
GPG Key transition (from rsa2048 to rsa4096) since 2024-04-24.
New key: rsa4096/61AD3D98ECDF2C8E 9D8B E14E 3F2A 9DD7 9199 28F1 61AD 3D98
ECDF 2C8E
Old key: rsa2048/457CE0A0804465C5 6EE1 95D1 886E 8FFB 810D 4324 457C E0A0
8044 65C5
Transition statement: http://www.corpit.ru/mjt/gpg-transition-2024.txt
