kernel/security/min_addr.c, branch linux-3.15.y

mmap_min_addr check CAP_SYS_RAWIO only for write

2010-05-14T09:03:15Z

Redirecting directly to lsm, here's the patch discussed on lkml: http://lkml.org/lkml/2010/4/22/219 The mmap_min_addr value is useful information for an admin to see without being root ("is my system vulnerable to kernel NULL pointer attacks?") and its setting is trivially easy for an attacker to determine by calling mmap() in PAGE_SIZE increments starting at 0, so trying to keep it private has no value. Only require CAP_SYS_RAWIO if changing the value, not reading it. Comment from Serge : Me, I like to write my passwords with light blue pen on dark blue paper, pasted on my window - if you're going to get my password, you're gonna get a headache. Signed-off-by: Kees Cook Acked-by: Serge Hallyn Signed-off-by: James Morris (cherry picked from commit 822cceec7248013821d655545ea45d1c6a9d15b3)

security/min_addr.c: make init_mmap_min_addr() static

2009-12-16T22:24:22Z

init_mmap_min_addr() is a pure_initcall and should be static. Signed-off-by: H Hartley Sweeten Signed-off-by: Andrew Morton Signed-off-by: James Morris

sysctl: require CAP_SYS_RAWIO to set mmap_min_addr

2009-11-08T21:34:22Z

Currently the mmap_min_addr value can only be bypassed during mmap when the task has CAP_SYS_RAWIO. However, the mmap_min_addr sysctl value itself can be adjusted to 0 if euid == 0, allowing a bypass without CAP_SYS_RAWIO. This patch adds a check for the capability before allowing mmap_min_addr to be changed. Signed-off-by: Kees Cook Acked-by: Serge Hallyn Signed-off-by: James Morris

sysctl: remove "struct file *" argument of ->proc_handler

2009-09-24T14:21:04Z

It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan Cc: David Howells Cc: "Eric W. Biederman" Cc: Al Viro Cc: Ralf Baechle Cc: Martin Schwidefsky Cc: Ingo Molnar Cc: "David S. Miller" Cc: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Security/SELinux: seperate lsm specific mmap_min_addr

2009-08-17T05:09:11Z

Currently SELinux enforcement of controls on the ability to map low memory is determined by the mmap_min_addr tunable. This patch causes SELinux to ignore the tunable and instead use a seperate Kconfig option specific to how much space the LSM should protect. The tunable will now only control the need for CAP_SYS_RAWIO and SELinux permissions will always protect the amount of low memory designated by CONFIG_LSM_MMAP_MIN_ADDR. This allows users who need to disable the mmap_min_addr controls (usual reason being they run WINE as a non-root user) to do so and still have SELinux controls preventing confined domains (like a web server) from being able to map some area of low memory. Signed-off-by: Eric Paris Signed-off-by: James Morris