"Serge E. Hallyn" <serge@xxxxxxxxxx> writes: > Quoting Eric W. Biederman (ebiederm@xxxxxxxxxxxx): >> "Serge E. Hallyn" <serge@xxxxxxxxxx> writes: >> >> > Quoting Eric W. Beiderman (ebiederm@xxxxxxxxxxxx): >> >> From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> >> >> >> >> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> >> >> --- >> >> fs/attr.c | 8 ++++---- >> >> fs/exec.c | 10 +++++----- >> >> fs/fcntl.c | 6 +++--- >> >> fs/ioprio.c | 4 ++-- >> >> fs/locks.c | 2 +- >> >> fs/namei.c | 8 ++++---- >> >> include/linux/quotaops.h | 4 ++-- >> >> 7 files changed, 21 insertions(+), 21 deletions(-) >> >> >> >> >> @@ -2120,7 +2120,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs) >> >> if (__get_dumpable(cprm.mm_flags) == 2) { >> >> /* Setuid core dump mode */ >> >> flag = O_EXCL; /* Stop rewrite attacks */ >> >> - cred->fsuid = 0; /* Dump root private */ >> >> + cred->fsuid = GLOBAL_ROOT_UID; /* Dump root private */ >> > >> > Sorry, one more - can this be the per-ns root uid? The coredumps should >> > be ok to belong to privileged users in the namespace right? >> >> I'm not certain it was clear when you were looking at this that >> this is about dumping core from suid applications, not normal >> applications. >> >> Looking at the code in commoncap and commit_creds it looks like it is a >> bug that we don't call set_dumpable(new, suid_dumpable) in common cap >> when we use file capabilities. I might be wrong but I think we escape > > We do, check kernel/cred.c:commit_creds(). So long as the new permitted > set is not a subset of the old one. > > Tested it to make absolutely sure. When I add file capabilities to a > program that otherwise dumps core (int *x = 0; *x = 0;), core dumps are > no longer generated. Thanks for testing. Just reading through I was not certain if we had the change in creds that commit_creds needed to trigger the set_dumpable logic. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html