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| author | Nicholas Piggin <npiggin@gmail.com> | 2018-08-29 21:56:56 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-21 09:21:55 +0100 |
| commit | c467bb652d448ed6f8e9c0e0e7047e6dec5c9e22 (patch) | |
| tree | 7da634e49c37b7692b1dab5d5b7c348ea0a958bf /arch | |
| parent | 8d16dd049428072519333e4ab6ed5df8084d1435 (diff) | |
| download | linux-stable-c467bb652d448ed6f8e9c0e0e7047e6dec5c9e22.tar.gz linux-stable-c467bb652d448ed6f8e9c0e0e7047e6dec5c9e22.tar.bz2 linux-stable-c467bb652d448ed6f8e9c0e0e7047e6dec5c9e22.zip | |
powerpc/64/module: REL32 relocation range check
[ Upstream commit b851ba02a6f3075f0f99c60c4bc30a4af80cf428 ]
The recent module relocation overflow crash demonstrated that we
have no range checking on REL32 relative relocations. This patch
implements a basic check, the same kernel that previously oopsed
and rebooted now continues with some of these errors when loading
the module:
module_64: x_tables: REL32 527703503449812 out of range!
Possibly other relocations (ADDR32, REL16, TOC16, etc.) should also have
overflow checks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/module_64.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index b8d61e019d06..f7b1203bdaee 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -685,7 +685,14 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, case R_PPC64_REL32: /* 32 bits relative (used by relative exception tables) */ - *(u32 *)location = value - (unsigned long)location; + /* Convert value to relative */ + value -= (unsigned long)location; + if (value + 0x80000000 > 0xffffffff) { + pr_err("%s: REL32 %li out of range!\n", + me->name, (long int)value); + return -ENOEXEC; + } + *(u32 *)location = value; break; case R_PPC64_TOCSAVE: |