From: Mark Brown broonie@kernel.org

[ Upstream commit 5c152c2f66f9368394b89ac90dc7483476ef7b88 ]

When arm64 signal context data overflows the base struct sigcontext it gets placed in an extra buffer pointed to by a record of type EXTRA_CONTEXT in the base struct sigcontext which is required to be the last record in the base struct sigframe. The current validation code attempts to check this by using GET_RESV_NEXT_HEAD() to step forward from the current record to the next but that is a macro which assumes it is being provided with a struct _aarch64_ctx and uses the size there to skip forward to the next record. Instead validate_extra_context() passes it a struct extra_context which has a separate size field. This compiles but results in us trying to validate a termination record in completely the wrong place, at best failing validation and at worst just segfaulting. Fix this by passing the struct _aarch64_ctx we meant to into the macro.

Signed-off-by: Mark Brown broonie@kernel.org Link: https://lore.kernel.org/r/20220829160703.874492-4-broonie@kernel.org Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/arm64/signal/testcases/testcases.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c index 61ebcdf63831..a3ac5c2d8aac 100644 --- a/tools/testing/selftests/arm64/signal/testcases/testcases.c +++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c @@ -33,7 +33,7 @@ bool validate_extra_context(struct extra_context *extra, char **err) return false;

fprintf(stderr, "Validating EXTRA...\n"); - term = GET_RESV_NEXT_HEAD(extra); + term = GET_RESV_NEXT_HEAD(&extra->head); if (!term || term->magic || term->size) { *err = "Missing terminator after EXTRA context"; return false;