handle suicide on late failure exits in execve() in search_binary_handler()

... rather than doing that in the guts of ->load_binary().
[updated to fix the bug spotted by Shentino - for SIGSEGV we really need
something stronger than send_sig_info(); again, better do that in one place]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 35 insertions, 77 deletions

diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index d21ff89207cd..df91466f973d 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -308,11 +308,8 @@ static int load_aout_binary(struct linux_binprm *bprm)
                 (current->mm->start_brk = N_BSSADDR(ex));
 
         retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
-        if (retval < 0) {
-                /* Someone check-me: is this error path enough? */
-                send_sig(SIGKILL, current, 0);
+        if (retval < 0)
                 return retval;
-        }
 
         install_exec_creds(bprm);
 
@@ -324,17 +321,13 @@ static int load_aout_binary(struct linux_binprm *bprm)
 
                 error = vm_brk(text_addr & PAGE_MASK, map_size);
 
-                if (error != (text_addr & PAGE_MASK)) {
-                        send_sig(SIGKILL, current, 0);
+                if (error != (text_addr & PAGE_MASK))
                         return error;
-                }
 
                 error = read_code(bprm->file, text_addr, 32,
                                   ex.a_text + ex.a_data);
-                if ((signed long)error < 0) {
-                        send_sig(SIGKILL, current, 0);
+                if ((signed long)error < 0)
                         return error;
-                }
         } else {
 #ifdef WARN_OLD
                 static unsigned long error_time, error_time2;
@@ -368,20 +361,16 @@ static int load_aout_binary(struct linux_binprm *bprm)
                                 MAP_EXECUTABLE | MAP_32BIT,
                                 fd_offset);
 
-                if (error != N_TXTADDR(ex)) {
-                        send_sig(SIGKILL, current, 0);
+                if (error != N_TXTADDR(ex))
                         return error;
-                }
 
                 error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
                                 PROT_READ | PROT_WRITE | PROT_EXEC,
                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
                                 MAP_EXECUTABLE | MAP_32BIT,
                                 fd_offset + ex.a_text);
-                if (error != N_DATADDR(ex)) {
-                        send_sig(SIGKILL, current, 0);
+                if (error != N_DATADDR(ex))
                         return error;
-                }
         }
 beyond_if:
         set_binfmt(&aout_format);
diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index ca0ba15a7306..929dec08c348 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -256,11 +256,8 @@ static int load_aout_binary(struct linux_binprm * bprm)
                 (current->mm->start_brk = N_BSSADDR(ex));
 
         retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
-        if (retval < 0) {
-                /* Someone check-me: is this error path enough? */
-                send_sig(SIGKILL, current, 0);
+        if (retval < 0)
                 return retval;
-        }
 
         install_exec_creds(bprm);
 
@@ -278,17 +275,13 @@ static int load_aout_binary(struct linux_binprm * bprm)
                 map_size = ex.a_text+ex.a_data;
 #endif
                 error = vm_brk(text_addr & PAGE_MASK, map_size);
-                if (error != (text_addr & PAGE_MASK)) {
-                        send_sig(SIGKILL, current, 0);
+                if (error != (text_addr & PAGE_MASK))
                         return error;
-                }
 
                 error = read_code(bprm->file, text_addr, pos,
                                   ex.a_text+ex.a_data);
-                if ((signed long)error < 0) {
-                        send_sig(SIGKILL, current, 0);
+                if ((signed long)error < 0)
                         return error;
-                }
         } else {
                 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
                     (N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
@@ -315,28 +308,22 @@ static int load_aout_binary(struct linux_binprm * bprm)
                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
                         fd_offset);
 
-                if (error != N_TXTADDR(ex)) {
-                        send_sig(SIGKILL, current, 0);
+                if (error != N_TXTADDR(ex))
                         return error;
-                }
 
                 error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
                                 PROT_READ | PROT_WRITE | PROT_EXEC,
                                 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
                                 fd_offset + ex.a_text);
-                if (error != N_DATADDR(ex)) {
-                        send_sig(SIGKILL, current, 0);
+                if (error != N_DATADDR(ex))
                         return error;
-                }
         }
 beyond_if:
         set_binfmt(&aout_format);
 
         retval = set_brk(current->mm->start_brk, current->mm->brk);
-        if (retval < 0) {
-                send_sig(SIGKILL, current, 0);
+        if (retval < 0)
                 return retval;
-        }
 
         current->mm->start_stack =
                 (unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 3892c1a23241..d8fc0605b9d2 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -738,10 +738,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
            change some of these later */
         retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
                                  executable_stack);
-        if (retval < 0) {
-                send_sig(SIGKILL, current, 0);
+        if (retval < 0)
                 goto out_free_dentry;
-        }
         
         current->mm->start_stack = bprm->p;
 
@@ -763,10 +761,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
                            and clear the area.  */
                         retval = set_brk(elf_bss + load_bias,
                                          elf_brk + load_bias);
-                        if (retval) {
-                                send_sig(SIGKILL, current, 0);
+                        if (retval)
                                 goto out_free_dentry;
-                        }
                         nbyte = ELF_PAGEOFFSET(elf_bss);
                         if (nbyte) {
                                 nbyte = ELF_MIN_ALIGN - nbyte;
@@ -820,7 +816,6 @@ static int load_elf_binary(struct linux_binprm *bprm)
                 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
                                 elf_prot, elf_flags, 0);
                 if (BAD_ADDR(error)) {
-                        send_sig(SIGKILL, current, 0);
                         retval = IS_ERR((void *)error) ?
                                 PTR_ERR((void*)error) : -EINVAL;
                         goto out_free_dentry;
@@ -851,7 +846,6 @@ static int load_elf_binary(struct linux_binprm *bprm)
                     elf_ppnt->p_memsz > TASK_SIZE ||
                     TASK_SIZE - elf_ppnt->p_memsz < k) {
                         /* set_brk can never work. Avoid overflows. */
-                        send_sig(SIGKILL, current, 0);
                         retval = -EINVAL;
                         goto out_free_dentry;
                 }
@@ -883,12 +877,9 @@ static int load_elf_binary(struct linux_binprm *bprm)
          * up getting placed where the bss needs to go.
          */
         retval = set_brk(elf_bss, elf_brk);
-        if (retval) {
-                send_sig(SIGKILL, current, 0);
+        if (retval)
                 goto out_free_dentry;
-        }
         if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
-                send_sig(SIGSEGV, current, 0);
                 retval = -EFAULT; /* Nobody gets to see this, but.. */
                 goto out_free_dentry;
         }
@@ -909,7 +900,6 @@ static int load_elf_binary(struct linux_binprm *bprm)
                         elf_entry += loc->interp_elf_ex.e_entry;
                 }
                 if (BAD_ADDR(elf_entry)) {
-                        force_sig(SIGSEGV, current);
                         retval = IS_ERR((void *)elf_entry) ?
                                         (int)elf_entry : -EINVAL;
                         goto out_free_dentry;
@@ -922,7 +912,6 @@ static int load_elf_binary(struct linux_binprm *bprm)
         } else {
                 elf_entry = loc->elf_ex.e_entry;
                 if (BAD_ADDR(elf_entry)) {
-                        force_sig(SIGSEGV, current);
                         retval = -EINVAL;
                         goto out_free_dentry;
                 }
@@ -934,19 +923,15 @@ static int load_elf_binary(struct linux_binprm *bprm)
 
 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
         retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
-        if (retval < 0) {
-                send_sig(SIGKILL, current, 0);
+        if (retval < 0)
                 goto out;
-        }
 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
 
         install_exec_creds(bprm);
         retval = create_elf_tables(bprm, &loc->elf_ex,
                           load_addr, interp_load_addr);
-        if (retval < 0) {
-                send_sig(SIGKILL, current, 0);
+        if (retval < 0)
                 goto out;
-        }
         /* N.B. passed_fileno might not be initialized? */
         current->mm->end_code = end_code;
         current->mm->start_code = start_code;
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index fe2a643ee005..d3634bfb7fe1 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -317,8 +317,8 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
                 goto error;
 
         /* there's now no turning back... the old userspace image is dead,
-         * defunct, deceased, etc. after this point we have to exit via
-         * error_kill */
+         * defunct, deceased, etc.
+         */
         set_personality(PER_LINUX_FDPIC);
         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
                 current->personality |= READ_IMPLIES_EXEC;
@@ -343,24 +343,22 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 
         retval = setup_arg_pages(bprm, current->mm->start_stack,
                                  executable_stack);
-        if (retval < 0) {
-                send_sig(SIGKILL, current, 0);
-                goto error_kill;
-        }
+        if (retval < 0)
+                goto error;
 #endif
 
         /* load the executable and interpreter into memory */
         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
                                     "executable");
         if (retval < 0)
-                goto error_kill;
+                goto error;
 
         if (interpreter_name) {
                 retval = elf_fdpic_map_file(&interp_params, interpreter,
                                             current->mm, "interpreter");
                 if (retval < 0) {
                         printk(KERN_ERR "Unable to load interpreter\n");
-                        goto error_kill;
+                        goto error;
                 }
 
                 allow_write_access(interpreter);
@@ -397,7 +395,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
         if (IS_ERR_VALUE(current->mm->start_brk)) {
                 retval = current->mm->start_brk;
                 current->mm->start_brk = 0;
-                goto error_kill;
+                goto error;
         }
 
         current->mm->brk = current->mm->start_brk;
@@ -410,7 +408,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
         install_exec_creds(bprm);
         if (create_elf_fdpic_tables(bprm, current->mm,
                                     &exec_params, &interp_params) < 0)
-                goto error_kill;
+                goto error;
 
         kdebug("- start_code  %lx", current->mm->start_code);
         kdebug("- end_code    %lx", current->mm->end_code);
@@ -449,12 +447,6 @@ error:
         kfree(interp_params.phdrs);
         kfree(interp_params.loadmap);
         return retval;
-
-        /* unrecoverable error - kill the process */
-error_kill:
-        send_sig(SIGSEGV, current, 0);
-        goto error;
-
 }
 
 /*****************************************************************************/
diff --git a/fs/exec.c b/fs/exec.c
index a2b42a98c743..7302b75a9820 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1372,18 +1372,23 @@ int search_binary_handler(struct linux_binprm *bprm)
                 read_unlock(&binfmt_lock);
                 bprm->recursion_depth++;
                 retval = fmt->load_binary(bprm);
+                read_lock(&binfmt_lock);
+                put_binfmt(fmt);
                 bprm->recursion_depth--;
-                if (retval >= 0 || retval != -ENOEXEC ||
-                    bprm->mm == NULL || bprm->file == NULL) {
-                        put_binfmt(fmt);
+                if (retval < 0 && !bprm->mm) {
+                        /* we got to flush_old_exec() and failed after it */
+                        read_unlock(&binfmt_lock);
+                        force_sigsegv(SIGSEGV, current);
+                        return retval;
+                }
+                if (retval != -ENOEXEC || !bprm->file) {
+                        read_unlock(&binfmt_lock);
                         return retval;
                 }
-                read_lock(&binfmt_lock);
-                put_binfmt(fmt);
         }
         read_unlock(&binfmt_lock);
 
-        if (need_retry && retval == -ENOEXEC) {
+        if (need_retry) {
                 if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
                     printable(bprm->buf[2]) && printable(bprm->buf[3]))
                         return retval;