5.0-stable review patch. If anyone has any objections, please let me know.
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From: Fredrik Noring noring@nocrew.org
commit 54a7151b1496cddbb7a83546b7998103e98edc88 upstream.
Fix commit 56067812d5b0 ("kbuild: modversions: add infrastructure for emitting relative CRCs") where CRCs are interpreted in host byte order rather than proper kernel byte order. The bug is conditional on CONFIG_MODULE_REL_CRCS.
For example, when loading a BE module into a BE kernel compiled with a LE system, the error "disagrees about version of symbol module_layout" is produced. A message such as "Found checksum D7FA6856 vs module 5668FAD7" will be given with debug enabled, which indicates an obvious endian problem within __kcrctab within the kernel image.
The general solution is to use the macro TO_NATIVE, as is done in similar cases throughout modpost.c. With this correction it has been verified that a BE kernel compiled with a LE system accepts BE modules.
This change has also been verified with a LE kernel compiled with a LE system, in which case TO_NATIVE returns its value unmodified since the byte orders match. This is by far the common case.
Fixes: 56067812d5b0 ("kbuild: modversions: add infrastructure for emitting relative CRCs") Signed-off-by: Fredrik Noring noring@nocrew.org Cc: stable@vger.kernel.org Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- scripts/mod/modpost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -640,7 +640,7 @@ static void handle_modversions(struct mo info->sechdrs[sym->st_shndx].sh_offset - (info->hdr->e_type != ET_REL ? info->sechdrs[sym->st_shndx].sh_addr : 0); - crc = *crcp; + crc = TO_NATIVE(*crcp); } sym_update_crc(symname + strlen("__crc_"), mod, crc, export);