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author | Cristian Marussi <cristian.marussi@arm.com> | 2019-10-25 18:57:16 +0100 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-11-08 11:10:50 +0000 |
commit | 49978aa8f079633192928cb966dcde39a3ff0747 (patch) | |
tree | f52e73233bf29db5327bdc4f63918c4fe759d07e /tools/testing/selftests/arm64/signal | |
parent | 46185cd1241b46c94933752137cde18ecfaf3766 (diff) | |
download | linux-stable-49978aa8f079633192928cb966dcde39a3ff0747.tar.gz linux-stable-49978aa8f079633192928cb966dcde39a3ff0747.tar.bz2 linux-stable-49978aa8f079633192928cb966dcde39a3ff0747.zip |
kselftest: arm64: fake_sigreturn_bad_size
Add a simple fake_sigreturn testcase which builds a ucontext_t with a
badly sized header that causes a overrun in the __reserved area and
place it onto the stack. Expects a SIGSEGV on test PASS.
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'tools/testing/selftests/arm64/signal')
-rw-r--r-- | tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c new file mode 100644 index 000000000000..b3c362100666 --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 ARM Limited + * + * Place a fake sigframe on the stack including a bad record overflowing + * the __reserved space: on sigreturn Kernel must spot this attempt and + * the test case is expected to be terminated via SEGV. + */ + +#include <signal.h> +#include <ucontext.h> + +#include "test_signals_utils.h" +#include "testcases.h" + +struct fake_sigframe sf; + +#define MIN_SZ_ALIGN 16 + +static int fake_sigreturn_bad_size_run(struct tdescr *td, + siginfo_t *si, ucontext_t *uc) +{ + size_t resv_sz, need_sz, offset; + struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head; + + /* just to fill the ucontext_t with something real */ + if (!get_current_context(td, &sf.uc)) + return 1; + + resv_sz = GET_SF_RESV_SIZE(sf); + /* at least HDR_SZ + bad sized esr_context needed */ + need_sz = sizeof(struct esr_context) + HDR_SZ; + head = get_starting_head(shead, need_sz, resv_sz, &offset); + if (!head) + return 0; + + /* + * Use an esr_context to build a fake header with a + * size greater then the free __reserved area minus HDR_SZ; + * using ESR_MAGIC here since it is not checked for size nor + * is limited to one instance. + * + * At first inject an additional normal esr_context + */ + head->magic = ESR_MAGIC; + head->size = sizeof(struct esr_context); + /* and terminate properly */ + write_terminator_record(GET_RESV_NEXT_HEAD(head)); + ASSERT_GOOD_CONTEXT(&sf.uc); + + /* + * now mess with fake esr_context size: leaving less space than + * needed while keeping size value 16-aligned + * + * It must trigger a SEGV from Kernel on: + * + * resv_sz - offset < sizeof(*head) + */ + /* at first set the maximum good 16-aligned size */ + head->size = (resv_sz - offset - need_sz + MIN_SZ_ALIGN) & ~0xfUL; + /* plus a bit more of 16-aligned sized stuff */ + head->size += MIN_SZ_ALIGN; + /* and terminate properly */ + write_terminator_record(GET_RESV_NEXT_HEAD(head)); + ASSERT_BAD_CONTEXT(&sf.uc); + fake_sigreturn(&sf, sizeof(sf), 0); + + return 1; +} + +struct tdescr tde = { + .name = "FAKE_SIGRETURN_BAD_SIZE", + .descr = "Triggers a sigreturn with a overrun __reserved area", + .sig_ok = SIGSEGV, + .timeout = 3, + .run = fake_sigreturn_bad_size_run, +}; |