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From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: Greg Ungerer <gerg@linux-m68k.org>, linux-fsdevel@vger.kernel.org
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	David Howells <dhowells@redhat.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org
Subject: [PATCH v5 03/15] binfmt_flat: prevent kernel dammage from corrupted executable headers
Date: Sun, 24 Jul 2016 11:30:17 -0400	[thread overview]
Message-ID: <1469374229-21585-4-git-send-email-nicolas.pitre@linaro.org> (raw)
In-Reply-To: <1469374229-21585-1-git-send-email-nicolas.pitre@linaro.org>

Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
 fs/binfmt_flat.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index c3ccdefdea..03301bad1f 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -466,6 +466,17 @@ static int load_flat_file(struct linux_binprm *bprm,
 	}
 
 	/*
+	 * Make sure the header params are sane.
+	 * 28 bits (256 MB) is way more than reasonable in this case.
+	 * If some top bits are set we have probable binary corruption.
+	*/
+	if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
+		pr_err("bad header\n");
+		ret = -ENOEXEC;
+		goto err;
+	}
+
+	/*
 	 * fix up the flags for the older format,  there were all kinds
 	 * of endian hacks,  this only works for the simple cases
 	 */
-- 
2.7.4


  parent reply	other threads:[~2016-07-24 15:30 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-24 15:30 [PATCH v5 00/15] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 01/15] binfmt_flat: assorted cleanups Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 02/15] binfmt_flat: convert printk invocations to their modern form Nicolas Pitre
2016-07-24 15:30 ` Nicolas Pitre [this message]
2016-07-24 15:30 ` [PATCH v5 04/15] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 05/15] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 06/15] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 07/15] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 08/15] binfmt_flat: use proper user space accessors with old relocs code Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 09/15] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 10/15] binfmt_flat: update libraries' data segment pointer with userspace accessors Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 11/15] binfmt_flat: add MMU-specific support Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 12/15] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
2016-07-24 19:48   ` Arnd Bergmann
2016-07-24 20:25     ` Nicolas Pitre
2016-07-25  8:18       ` Arnd Bergmann
2016-07-24 15:30 ` [PATCH v5 13/15] m68k: fix bFLT executable running on MMU enabled systems Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 14/15] m68k: enable binfmt_flat on systems with an MMU Nicolas Pitre
2016-07-24 15:30 ` [PATCH v5 15/15] ARM: " Nicolas Pitre
2016-07-26  0:53 ` [PATCH v5 00/15] allow BFLT executables on systems with a MMU Greg Ungerer

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