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| author |   Nicholas Piggin <npiggin@gmail.com> | 2018-08-29 21:56:56 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2018-10-20 13:26:47 +1100 |
| commit | b851ba02a6f3075f0f99c60c4bc30a4af80cf428 (patch) | |
| tree | 249ea33c51fff3d0220c994c2e7f2e883e9e017f /arch/powerpc/kernel | |
| parent | powerpc/64s/radix: Fix radix__flush_tlb_collapsed_pmd double flushing pmd (diff) | |
| download | linux-dev-b851ba02a6f3075f0f99c60c4bc30a4af80cf428.tar.xz linux-dev-b851ba02a6f3075f0f99c60c4bc30a4af80cf428.zip | |
powerpc/64/module: REL32 relocation range check
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>
Diffstat (limited to 'arch/powerpc/kernel')
| -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 2c53de9f3b6a..8661eea78503 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -680,7 +680,14 @@ 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: |