Messages in this thread Patch in this message | | | Date | Thu, 27 Jul 2006 18:27:24 +0800 | From | Eugene Teo <> | Subject | [PATCH] Require mmap handler for a.out executables (was Re: 2.6.18-rc2-mm1) |
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Hi Andrew,
Andrew Morton wrote: [snipped] > - Lots of random patches. Many of them are bugfixes and I shall, as usual, > go through them all identifying 2.6.18 material. But I can miss things, so > please don't be afraid to point 2.6.18 candidates out to me. [snipped]
The following patch provides better protection against people exploiting stuff in /proc and I hope you consider it for upstream inclusion.
Thanks.
Eugene
[PATCH] Require mmap handler for a.out executables
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@redhat.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
--- commit 1597cf8405734e4747c808bb7e04115a6670dccf tree 49050549aee6406dab0c021c5aa4e9bfc337bd8f parent 44eb123126d289bac398cac0232309c228386671 author Marcel Holtmann <marcel@holtmann.org> Wed, 26 Jul 2006 12:12:14 +0200 committer Marcel Holtmann <marcel@holtmann.org> Wed, 26 Jul 2006 12:12:14 +0200
fs/binfmt_aout.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c index f312103..5638acf 100644 --- a/fs/binfmt_aout.c +++ b/fs/binfmt_aout.c @@ -278,6 +278,9 @@ static int load_aout_binary(struct linux return -ENOEXEC; }
+ 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 +479,9 @@ static int load_aout_library(struct file goto out; }
+ if (!file->f_op || !file->f_op->mmap) + goto out; + if (N_FLAGS(ex)) goto out;
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