bin_elf_fdpic: check the return value of clear_user

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 8 deletions

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index f3e72c5c19f5..70cfc4b84ae0 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -972,9 +972,12 @@ static int elf_fdpic_map_file_constdisp_on_uclinux(
                         params->elfhdr_addr = seg->addr;
 
                 /* clear any space allocated but not loaded */
-                if (phdr->p_filesz < phdr->p_memsz)
-                        clear_user((void *) (seg->addr + phdr->p_filesz),
-                                   phdr->p_memsz - phdr->p_filesz);
+                if (phdr->p_filesz < phdr->p_memsz) {
+                        ret = clear_user((void *) (seg->addr + phdr->p_filesz),
+                                         phdr->p_memsz - phdr->p_filesz);
+                        if (ret)
+                                return ret;
+                }
 
                 if (mm) {
                         if (phdr->p_flags & PF_X) {
@@ -1014,7 +1017,7 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
         struct elf32_fdpic_loadseg *seg;
         struct elf32_phdr *phdr;
         unsigned long load_addr, delta_vaddr;
-        int loop, dvset;
+        int loop, dvset, ret;
 
         load_addr = params->load_addr;
         delta_vaddr = 0;
@@ -1114,7 +1117,9 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
                  * PT_LOAD */
                 if (prot & PROT_WRITE && disp > 0) {
                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
-                        clear_user((void __user *) maddr, disp);
+                        ret = clear_user((void __user *) maddr, disp);
+                        if (ret)
+                                return ret;
                         maddr += disp;
                 }
 
@@ -1149,15 +1154,19 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
                 if (prot & PROT_WRITE && excess1 > 0) {
                         kdebug("clear[%d] ad=%lx sz=%lx",
                                loop, maddr + phdr->p_filesz, excess1);
-                        clear_user((void __user *) maddr + phdr->p_filesz,
-                                   excess1);
+                        ret = clear_user((void __user *) maddr + phdr->p_filesz,
+                                         excess1);
+                        if (ret)
+                                return ret;
                 }
 
 #else
                 if (excess > 0) {
                         kdebug("clear[%d] ad=%lx sz=%lx",
                                loop, maddr + phdr->p_filesz, excess);
-                        clear_user((void *) maddr + phdr->p_filesz, excess);
+                        ret = clear_user((void *) maddr + phdr->p_filesz, excess);
+                        if (ret)
+                                return ret;
                 }
 #endif