Messages in this thread | | | Subject | Re: [PATCH 1/2] security: let security modules use PTRACE_MODE_* with bitmasks | From | Casey Schaufler <> | Date | Mon, 7 Dec 2015 13:51:50 -0800 |
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On 12/7/2015 1:25 PM, Jann Horn wrote: > It looks like smack and yama weren't aware that the ptrace mode > can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but > only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch, > all modes have flags ORed into them. > > Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
> --- > security/smack/smack_lsm.c | 8 +++----- > security/yama/yama_lsm.c | 4 ++-- > 2 files changed, 5 insertions(+), 7 deletions(-) > > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index ff81026..7c57c7f 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -398,12 +398,10 @@ static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, > */ > static inline unsigned int smk_ptrace_mode(unsigned int mode) > { > - switch (mode) { > - case PTRACE_MODE_READ: > - return MAY_READ; > - case PTRACE_MODE_ATTACH: > + if (mode & PTRACE_MODE_ATTACH) > return MAY_READWRITE; > - } > + if (mode & PTRACE_MODE_READ) > + return MAY_READ; > > return 0; > } > diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c > index d3c19c9..cb6ed10 100644 > --- a/security/yama/yama_lsm.c > +++ b/security/yama/yama_lsm.c > @@ -281,7 +281,7 @@ static int yama_ptrace_access_check(struct task_struct *child, > int rc = 0; > > /* require ptrace target be a child of ptracer on attach */ > - if (mode == PTRACE_MODE_ATTACH) { > + if (mode & PTRACE_MODE_ATTACH) { > switch (ptrace_scope) { > case YAMA_SCOPE_DISABLED: > /* No additional restrictions. */ > @@ -307,7 +307,7 @@ static int yama_ptrace_access_check(struct task_struct *child, > } > } > > - if (rc) { > + if (rc && (mode & PTRACE_MODE_NOAUDIT) == 0) { > printk_ratelimited(KERN_NOTICE > "ptrace of pid %d was attempted by: %s (pid %d)\n", > child->pid, current->comm, current->pid);
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