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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-20 12:43:53 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-10-25 15:56:29 -0500 |
| commit | 83a1f27ad773b1d8f0460d3a676114c7651918cc (patch) | |
| tree | 2006910cad1b0b66d87c2f11c36b9afb4e8fc2a8 /arch/powerpc | |
| parent | ce0ee4e6ac99606f3945f4d47775544edc3f7985 (diff) | |
| download | linux-stable-83a1f27ad773b1d8f0460d3a676114c7651918cc.tar.gz linux-stable-83a1f27ad773b1d8f0460d3a676114c7651918cc.tar.bz2 linux-stable-83a1f27ad773b1d8f0460d3a676114c7651918cc.zip | |
signal/powerpc: On swapcontext failure force SIGSEGV
If the register state may be partial and corrupted instead of calling
do_exit, call force_sigsegv(SIGSEGV). Which properly kills the
process with SIGSEGV and does not let any more userspace code execute,
instead of just killing one thread of the process and potentially
confusing everything.
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
History-tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Fixes: 756f1ae8a44e ("PPC32: Rework signal code and add a swapcontext system call.")
Fixes: 04879b04bf50 ("[PATCH] ppc64: VMX (Altivec) support & signal32 rework, from Ben Herrenschmidt")
Link: https://lkml.kernel.org/r/20211020174406.17889-7-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 9 |
2 files changed, 10 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 0608581967f0..666f3da41232 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -1062,8 +1062,10 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, * or if another thread unmaps the region containing the context. * We kill the task with a SIGSEGV in this situation. */ - if (do_setcontext(new_ctx, regs, 0)) - do_exit(SIGSEGV); + if (do_setcontext(new_ctx, regs, 0)) { + force_sigsegv(SIGSEGV); + return -EFAULT; + } set_thread_flag(TIF_RESTOREALL); return 0; diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 1831bba0582e..d8de622c9e4a 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -703,15 +703,18 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, * We kill the task with a SIGSEGV in this situation. */ - if (__get_user_sigset(&set, &new_ctx->uc_sigmask)) - do_exit(SIGSEGV); + if (__get_user_sigset(&set, &new_ctx->uc_sigmask)) { + force_sigsegv(SIGSEGV); + return -EFAULT; + } set_current_blocked(&set); if (!user_read_access_begin(new_ctx, ctx_size)) return -EFAULT; if (__unsafe_restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) { user_read_access_end(); - do_exit(SIGSEGV); + force_sigsegv(SIGSEGV); + return -EFAULT; } user_read_access_end(); |