Re: [PATCH 3/3-v2] security: allow capable check to permit mmap or low vm space
On Mon, 26 Nov 2007, Eric Paris wrote: > On a kernel with CONFIG_SECURITY but without an LSM which implements > security_file_mmap it is impossible for an application to mmap addresses > lower than mmap_min_addr. Based on a suggestion from a developer in the > openwall community this patch adds a check for CAP_SYS_RAWIO. It is > assumed that any process with this capability can harm the system a lot > more easily than writing some stuff on the zero page and then trying to > get the kernel to trip over itself. It also means that programs like X > on i686 which use vm86 emulation can work even with mmap_min_addr set. > > Signed-off-by: Eric Paris <[EMAIL PROTECTED]> Applied to git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-akpm If nobody hollers, I'll push it to Linus when the next merge window opens. - James -- James Morris <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/3-v2] security: allow capable check to permit mmap or low vm space
On a kernel with CONFIG_SECURITY but without an LSM which implements
security_file_mmap it is impossible for an application to mmap addresses
lower than mmap_min_addr. Based on a suggestion from a developer in the
openwall community this patch adds a check for CAP_SYS_RAWIO. It is
assumed that any process with this capability can harm the system a lot
more easily than writing some stuff on the zero page and then trying to
get the kernel to trip over itself. It also means that programs like X
on i686 which use vm86 emulation can work even with mmap_min_addr set.
Signed-off-by: Eric Paris <[EMAIL PROTECTED]>
---
security/dummy.c |2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/security/dummy.c b/security/dummy.c
index 6d895ad..3ccfbbe 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -426,7 +426,7 @@ static int dummy_file_mmap (struct file *file, unsigned
long reqprot,
unsigned long addr,
unsigned long addr_only)
{
- if (addr < mmap_min_addr)
+ if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO))
return -EACCES;
return 0;
}
-
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[PATCH 3/3-v2] security: allow capable check to permit mmap or low vm space
On a kernel with CONFIG_SECURITY but without an LSM which implements
security_file_mmap it is impossible for an application to mmap addresses
lower than mmap_min_addr. Based on a suggestion from a developer in the
openwall community this patch adds a check for CAP_SYS_RAWIO. It is
assumed that any process with this capability can harm the system a lot
more easily than writing some stuff on the zero page and then trying to
get the kernel to trip over itself. It also means that programs like X
on i686 which use vm86 emulation can work even with mmap_min_addr set.
Signed-off-by: Eric Paris [EMAIL PROTECTED]
---
security/dummy.c |2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/security/dummy.c b/security/dummy.c
index 6d895ad..3ccfbbe 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -426,7 +426,7 @@ static int dummy_file_mmap (struct file *file, unsigned
long reqprot,
unsigned long addr,
unsigned long addr_only)
{
- if (addr mmap_min_addr)
+ if ((addr mmap_min_addr) !capable(CAP_SYS_RAWIO))
return -EACCES;
return 0;
}
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3-v2] security: allow capable check to permit mmap or low vm space
On Mon, 26 Nov 2007, Eric Paris wrote: On a kernel with CONFIG_SECURITY but without an LSM which implements security_file_mmap it is impossible for an application to mmap addresses lower than mmap_min_addr. Based on a suggestion from a developer in the openwall community this patch adds a check for CAP_SYS_RAWIO. It is assumed that any process with this capability can harm the system a lot more easily than writing some stuff on the zero page and then trying to get the kernel to trip over itself. It also means that programs like X on i686 which use vm86 emulation can work even with mmap_min_addr set. Signed-off-by: Eric Paris [EMAIL PROTECTED] Applied to git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-akpm If nobody hollers, I'll push it to Linus when the next merge window opens. - James -- James Morris [EMAIL PROTECTED] - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
