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authorNicolas Pitre <nicolas.pitre@linaro.org>2016-07-24 17:30:21 +0200
committerGreg Ungerer <gerg@linux-m68k.org>2016-07-25 08:52:06 +0200
commit6e572ffe3feb8a02ed0044987654e07670aeffc2 (patch)
tree66198e5622e32f4ed2eba4c932cae58a515c3cc9 /fs/binfmt_flat.c
parentbinfmt_flat: clean up create_flat_tables() and stack accesses (diff)
downloadlinux-6e572ffe3feb8a02ed0044987654e07670aeffc2.tar.xz
linux-6e572ffe3feb8a02ed0044987654e07670aeffc2.zip
binfmt_flat: use proper user space accessors with relocs processing code
Relocs are fixed up in place in user space memory. The appropriate accessors are required for this code to work with an active MMU. The architecture specific handlers flat_get_addr_from_rp() and flat_put_addr_at_rp() for ARM and M68K are adjusted with separate patches. SuperH and Xtensa are left out as they doesn't implement __get_user_unaligned() and __put_user_unaligned() yet. The other architectures that use BFLT don't have any MMU. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Diffstat (limited to 'fs/binfmt_flat.c')
-rw-r--r--fs/binfmt_flat.c31
1 files changed, 19 insertions, 12 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 5dc7968a424f..9deafb282db5 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -419,7 +419,7 @@ static int load_flat_file(struct linux_binprm *bprm,
unsigned long textpos, datapos, realdatastart;
unsigned long text_len, data_len, bss_len, stack_len, full_data, flags;
unsigned long len, memp, memp_size, extra, rlim;
- unsigned long *reloc, *rp;
+ unsigned long __user *reloc, *rp;
struct inode *inode;
int i, rev, relocs;
loff_t fpos;
@@ -591,7 +591,7 @@ static int load_flat_file(struct linux_binprm *bprm,
goto err;
}
- reloc = (unsigned long *)
+ reloc = (unsigned long __user *)
(datapos + (ntohl(hdr->reloc_start) - text_len));
memp = realdatastart;
memp_size = len;
@@ -616,7 +616,7 @@ static int load_flat_file(struct linux_binprm *bprm,
MAX_SHARED_LIBS * sizeof(unsigned long),
FLAT_DATA_ALIGN);
- reloc = (unsigned long *)
+ reloc = (unsigned long __user *)
(datapos + (ntohl(hdr->reloc_start) - text_len));
memp = textpos;
memp_size = len;
@@ -708,15 +708,20 @@ static int load_flat_file(struct linux_binprm *bprm,
* image.
*/
if (flags & FLAT_FLAG_GOTPIC) {
- for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
- unsigned long addr;
- if (*rp) {
- addr = calc_reloc(*rp, libinfo, id, 0);
+ for (rp = (unsigned long __user *)datapos; ; rp++) {
+ unsigned long addr, rp_val;
+ if (get_user(rp_val, rp))
+ return -EFAULT;
+ if (rp_val == 0xffffffff)
+ break;
+ if (rp_val) {
+ addr = calc_reloc(rp_val, libinfo, id, 0);
if (addr == RELOC_FAILED) {
ret = -ENOEXEC;
goto err;
}
- *rp = addr;
+ if (put_user(addr, rp))
+ return -EFAULT;
}
}
}
@@ -733,7 +738,7 @@ static int load_flat_file(struct linux_binprm *bprm,
* __start to address 4 so that is okay).
*/
if (rev > OLD_FLAT_VERSION) {
- unsigned long persistent = 0;
+ unsigned long __maybe_unused persistent = 0;
for (i = 0; i < relocs; i++) {
unsigned long addr, relval;
@@ -742,12 +747,14 @@ static int load_flat_file(struct linux_binprm *bprm,
* relocated (of course, the address has to be
* relocated first).
*/
- relval = ntohl(reloc[i]);
+ if (get_user(relval, reloc + i))
+ return -EFAULT;
+ relval = ntohl(relval);
if (flat_set_persistent(relval, &persistent))
continue;
addr = flat_get_relocate_addr(relval);
- rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
- if (rp == (unsigned long *)RELOC_FAILED) {
+ rp = (unsigned long __user *)calc_reloc(addr, libinfo, id, 1);
+ if (rp == (unsigned long __user *)RELOC_FAILED) {
ret = -ENOEXEC;
goto err;
}