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| author | Andrew Vagin <avagin@openvz.org> | 2012-12-17 16:03:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-17 17:15:22 -0800 |
| commit | 7b9a7ec565505699f503b4fcf61500dceb36e744 (patch) | |
| tree | 1a0c3f91d613e4e07e858ba93e28344056356c7c | |
| parent | 992fb6e170639b0849bace8e49bf31bd37c4123c (diff) | |
| download | kernel-common-7b9a7ec565505699f503b4fcf61500dceb36e744.tar.gz kernel-common-7b9a7ec565505699f503b4fcf61500dceb36e744.tar.bz2 kernel-common-7b9a7ec565505699f503b4fcf61500dceb36e744.zip | |
proc: don't show nonexistent capabilities
Without this patch it is really hard to interpret a bounding set, if
CAP_LAST_CAP is unknown for a current kernel.
Non-existant capabilities can not be deleted from a bounding set with help
of prctl.
E.g.: Here are two examples without/with this patch.
CapBnd: ffffffe0fdecffff
CapBnd: 00000000fdecffff
I suggest to hide non-existent capabilities. Here is two reasons.
* It's logically and easier for using.
* It helps to checkpoint-restore capabilities of tasks, because tasks
can be restored on another kernel, where CAP_LAST_CAP is bigger.
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Andrew G. Morgan <morgan@kernel.org>
Reviewed-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/proc/array.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index d3696708fc1a..377a37366dde 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -308,6 +308,10 @@ static void render_cap_t(struct seq_file *m, const char *header, seq_putc(m, '\n'); } +/* Remove non-existent capabilities */ +#define NORM_CAPS(v) (v.cap[CAP_TO_INDEX(CAP_LAST_CAP)] &= \ + CAP_TO_MASK(CAP_LAST_CAP + 1) - 1) + static inline void task_cap(struct seq_file *m, struct task_struct *p) { const struct cred *cred; @@ -321,6 +325,11 @@ static inline void task_cap(struct seq_file *m, struct task_struct *p) cap_bset = cred->cap_bset; rcu_read_unlock(); + NORM_CAPS(cap_inheritable); + NORM_CAPS(cap_permitted); + NORM_CAPS(cap_effective); + NORM_CAPS(cap_bset); + render_cap_t(m, "CapInh:\t", &cap_inheritable); render_cap_t(m, "CapPrm:\t", &cap_permitted); render_cap_t(m, "CapEff:\t", &cap_effective); |