From 9227dd2a84a765fcfef1677ff17de0958b192eda Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 23 Jan 2017 17:26:31 +1300 Subject: exec: Remove LSM_UNSAFE_PTRACE_CAP With previous changes every location that tests for LSM_UNSAFE_PTRACE_CAP also tests for LSM_UNSAFE_PTRACE making the LSM_UNSAFE_PTRACE_CAP redundant, so remove it. Signed-off-by: "Eric W. Biederman" --- fs/exec.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'fs/exec.c') diff --git a/fs/exec.c b/fs/exec.c index e57946610733..c195ebb8e2aa 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1426,12 +1426,8 @@ static void check_unsafe_exec(struct linux_binprm *bprm) struct task_struct *p = current, *t; unsigned n_fs; - if (p->ptrace) { - if (ptracer_capable(p, current_user_ns())) - bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP; - else - bprm->unsafe |= LSM_UNSAFE_PTRACE; - } + if (p->ptrace) + bprm->unsafe |= LSM_UNSAFE_PTRACE; /* * This isn't strictly necessary, but it makes it harder for LSMs to -- cgit v1.2.2 From fea6d2a610c899bb7fd8e95fcbf46900b886e5a3 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Mon, 13 Feb 2017 15:45:26 -0500 Subject: vfs: Use upper filesystem inode in bprm_fill_uid() Right now bprm_fill_uid() uses inode fetched from file_inode(bprm->file). This in turn returns inode of lower filesystem (in a stacked filesystem setup). I was playing with modified patches of shiftfs posted by james bottomley and realized that through shiftfs setuid bit does not take effect. And reason being that we fetch uid/gid from inode of lower fs (and not from shiftfs inode). And that results in following checks failing. /* We ignore suid/sgid if there are no mappings for them in the ns */ if (!kuid_has_mapping(bprm->cred->user_ns, uid) || !kgid_has_mapping(bprm->cred->user_ns, gid)) return; uid/gid fetched from lower fs inode might not be mapped inside the user namespace of container. So we need to look at uid/gid fetched from upper filesystem (shiftfs in this particular case) and these should be mapped and setuid bit can take affect. Signed-off-by: Vivek Goyal Signed-off-by: Eric W. Biederman --- fs/exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/exec.c') diff --git a/fs/exec.c b/fs/exec.c index c195ebb8e2aa..698a86094f76 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1475,7 +1475,7 @@ static void bprm_fill_uid(struct linux_binprm *bprm) if (task_no_new_privs(current)) return; - inode = file_inode(bprm->file); + inode = bprm->file->f_path.dentry->d_inode; mode = READ_ONCE(inode->i_mode); if (!(mode & (S_ISUID|S_ISGID))) return; -- cgit v1.2.2