From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
David Howells <dhowells@redhat.com>,
Greg Ungerer <gerg@linux-m68k.org>
Subject: [PATCH v4 08/12] binfmt_flat: use proper user space accessors with old relocs code
Date: Wed, 20 Jul 2016 15:22:37 -0400 [thread overview]
Message-ID: <1469042561-7360-9-git-send-email-nicolas.pitre@linaro.org> (raw)
In-Reply-To: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
---
fs/binfmt_flat.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 9deafb282d..63756ca6a7 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -379,35 +379,38 @@ static void old_reloc(unsigned long rl)
{
static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
flat_v2_reloc_t r;
- unsigned long *ptr;
+ unsigned long __user *ptr;
+ unsigned long val;
r.value = rl;
#if defined(CONFIG_COLDFIRE)
- ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
+ ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
#else
- ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
+ ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
#endif
+ __get_user(val, ptr);
pr_debug("Relocation of variable at DATASEG+%x "
"(address %p, currently %lx) into segment %s\n",
- r.reloc.offset, ptr, *ptr, segment[r.reloc.type]);
+ r.reloc.offset, ptr, val, segment[r.reloc.type]);
switch (r.reloc.type) {
case OLD_FLAT_RELOC_TYPE_TEXT:
- *ptr += current->mm->start_code;
+ val += current->mm->start_code;
break;
case OLD_FLAT_RELOC_TYPE_DATA:
- *ptr += current->mm->start_data;
+ val += current->mm->start_data;
break;
case OLD_FLAT_RELOC_TYPE_BSS:
- *ptr += current->mm->end_data;
+ val += current->mm->end_data;
break;
default:
pr_err("Unknown relocation type=%x\n", r.reloc.type);
break;
}
+ __put_user(val, ptr);
- pr_debug("Relocation became %lx\n", *ptr);
+ pr_debug("Relocation became %lx\n", val);
}
/****************************************************************************/
@@ -780,8 +783,13 @@ static int load_flat_file(struct linux_binprm *bprm,
}
}
} else {
- for (i = 0; i < relocs; i++)
- old_reloc(ntohl(reloc[i]));
+ for (i = 0; i < relocs; i++) {
+ unsigned long relval;
+ if (get_user(relval, reloc + i))
+ return -EFAULT;
+ relval = ntohl(relval);
+ old_reloc(relval);
+ }
}
flush_icache_range(start_code, end_code);
--
2.7.4
next prev parent reply other threads:[~2016-07-20 19:22 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-20 19:22 [PATCH v4 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 01/12] binfmt_flat: assorted cleanups Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 02/12] binfmt_flat: convert printk invocations to their modern form Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 04/12] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 05/12] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 06/12] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 07/12] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
2016-07-20 19:22 ` Nicolas Pitre [this message]
2016-07-20 19:22 ` [PATCH v4 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 11/12] binfmt_flat: add MMU-specific support Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 12/12] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
2016-07-21 6:58 ` [PATCH v4 00/12] allow BFLT executables on systems with a MMU Greg Ungerer
2016-07-21 14:48 ` Nicolas Pitre
2016-07-22 7:28 ` Greg Ungerer
2016-07-22 15:06 ` One Thousand Gnomes
2016-07-22 19:22 ` Russell King - ARM Linux
2016-07-22 19:45 ` Nicolas Pitre
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