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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: linux-kernel@vger.kernel.org
Subject: [RFC PATCH 2/2] binfmt_elf: Uninitialized variable
Date: Wed, 19 Sep 2012 15:45:01 +0100	[thread overview]
Message-ID: <20120919144446.16893.24530.stgit@localhost.localdomain> (raw)
In-Reply-To: <20120919144410.16893.57933.stgit@localhost.localdomain>

From: Alan Cox <alan@linux.intel.com>

load_elf_interp has interp_map_addr carefully described as
"uninitialized_var" and marked so as to avoid a warning. However
if you trace the code it is passed into load_elf_interp and then
this value is checked against NULL.

As this return value isn't used this is actually safe but it freaks
various analysis tools that see un-initialized memory addresses
being read before their value is ever defined.

Set it to NULL as a matter of programming good taste if nothing else

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 fs/binfmt_elf.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index bf6d82b..5fb4801 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -880,7 +880,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 	}
 
 	if (elf_interpreter) {
-		unsigned long uninitialized_var(interp_map_addr);
+		unsigned long interp_map_addr = 0;
 
 		elf_entry = load_elf_interp(&loc->interp_elf_ex,
 					    interpreter,


  reply	other threads:[~2012-09-19 14:27 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-19 14:44 [RFC PATCH 1/2] binfmt_elf: Fix corner case kfree of uninitialized data Alan Cox
2012-09-19 14:45 ` Alan Cox [this message]
2012-09-26 23:25   ` [RFC PATCH 2/2] binfmt_elf: Uninitialized variable Andrew Morton
2012-09-26 23:21 ` [RFC PATCH 1/2] binfmt_elf: Fix corner case kfree of uninitialized data Andrew Morton

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