The patch titled
Require mmap handler for a.out executables
has been added to the -mm tree. Its filename is
require-mmap-handler-for-aout-executables.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Require mmap handler for a.out executables
From: Eugene Teo <eteo@xxxxxxxxxx>
Files supported by fs/proc/base.c, i.e. /proc/<pid>/*, are not capable of
meeting the validity checks in ELF load_elf_*() handling because they have
no mmap handler which is required by ELF. In order to stop a.out
executables being used as part of an exploit attack against /proc-related
vulnerabilities, we make a.out executables depend on ->mmap() existing.
Signed-off-by: Eugene Teo <eteo@xxxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/binfmt_aout.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff -puN fs/binfmt_aout.c~require-mmap-handler-for-aout-executables fs/binfmt_aout.c
--- a/fs/binfmt_aout.c~require-mmap-handler-for-aout-executables
+++ a/fs/binfmt_aout.c
@@ -278,6 +278,13 @@ static int load_aout_binary(struct linux
return -ENOEXEC;
}
+ /*
+ * Requires a mmap handler. This prevents people from using a.out
+ * as part of an exploit attack against /proc-related vulnerabilities.
+ */
+ if (!bprm->file->f_op || !bprm->file->f_op->mmap)
+ return -ENOEXEC;
+
fd_offset = N_TXTOFF(ex);
/* Check initial limits. This avoids letting people circumvent
@@ -476,6 +483,13 @@ static int load_aout_library(struct file
goto out;
}
+ /*
+ * Requires a mmap handler. This prevents people from using a.out
+ * as part of an exploit attack against /proc-related vulnerabilities.
+ */
+ if (!file->f_op || !file->f_op->mmap)
+ goto out;
+
if (N_FLAGS(ex))
goto out;
_
Patches currently in -mm which might be from eteo@xxxxxxxxxx are
require-mmap-handler-for-aout-executables.patch
-
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