173 lines
5.0 KiB
Diff
173 lines
5.0 KiB
Diff
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From f785c53174fd0ebad913e105382360f9d46205d8 Mon Sep 17 00:00:00 2001
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From: Petr Lautrbach <plautrba@redhat.com>
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Date: Tue, 31 May 2022 13:37:12 +0200
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Subject: [PATCH] Revert "libselinux: restorecon: pin file to avoid TOCTOU
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issues"
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Content-type: text/plain
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This reverts commit 7e979b56fd2cee28f647376a7233d2ac2d12ca50.
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The reverted commit broke `setfiles` when it's run from a chroot
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without /proc mounted, e.g.
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# chroot /mnt/sysimage
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chroot# setfiles -e /proc -e /sys /sys /etc/selinux/targeted/contexts/files/file_contexts /
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[strace]
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openat(AT_FDCWD, "/", O_RDONLY|O_EXCL|O_NOFOLLOW|O_PATH) = 3
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newfstatat(3, "", {st_mode=S_IFDIR|0555, st_size=4096, ...}, AT_EMPTY_PATH) = 0
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mmap(NULL, 2101248, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f1697c91000
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fgetxattr(3, "security.selinux", 0x55be8881d3f0, 255) = -1 EBADF (Bad file descriptor)
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fcntl(3, F_GETFL) = 0x220000 (flags O_RDONLY|O_NOFOLLOW|O_PATH)
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getxattr("/proc/self/fd/3", "security.selinux", 0x55be8881d3f0, 255) = -1 ENOENT (No such file or directory)
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[/strace]
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setfiles: Could not set context for /: No such file or directory
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Signed-off-by: Petr Lautrbach <plautrba@redhat.com>
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---
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libselinux/src/selinux_restorecon.c | 43 ++++++++++++-----------------
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1 file changed, 18 insertions(+), 25 deletions(-)
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diff --git a/libselinux/src/selinux_restorecon.c b/libselinux/src/selinux_restorecon.c
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index dc222b425c95..a50005353265 100644
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--- a/libselinux/src/selinux_restorecon.c
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+++ b/libselinux/src/selinux_restorecon.c
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@@ -623,13 +623,13 @@ out:
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return rc;
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}
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-static int restorecon_sb(const char *pathname, struct rest_flags *flags, bool first)
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+static int restorecon_sb(const char *pathname, const struct stat *sb,
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+ struct rest_flags *flags, bool first)
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{
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char *newcon = NULL;
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char *curcon = NULL;
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char *newtypecon = NULL;
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- int fd = -1, rc;
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- struct stat stat_buf;
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+ int rc;
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bool updated = false;
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const char *lookup_path = pathname;
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float pc;
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@@ -644,21 +644,13 @@ static int restorecon_sb(const char *pathname, struct rest_flags *flags, bool fi
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lookup_path += rootpathlen;
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}
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- fd = open(pathname, O_PATH | O_NOFOLLOW | O_EXCL);
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- if (fd < 0)
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- goto err;
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-
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- rc = fstat(fd, &stat_buf);
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- if (rc < 0)
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- goto err;
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-
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if (rootpath != NULL && lookup_path[0] == '\0')
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/* this is actually the root dir of the alt root. */
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rc = selabel_lookup_raw(fc_sehandle, &newcon, "/",
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- stat_buf.st_mode);
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+ sb->st_mode);
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else
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rc = selabel_lookup_raw(fc_sehandle, &newcon, lookup_path,
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- stat_buf.st_mode);
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+ sb->st_mode);
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if (rc < 0) {
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if (errno == ENOENT) {
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@@ -667,10 +659,10 @@ static int restorecon_sb(const char *pathname, struct rest_flags *flags, bool fi
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"Warning no default label for %s\n",
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lookup_path);
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- goto out; /* no match, but not an error */
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+ return 0; /* no match, but not an error */
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}
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- goto err;
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+ return -1;
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}
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if (flags->progress) {
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@@ -690,17 +682,19 @@ static int restorecon_sb(const char *pathname, struct rest_flags *flags, bool fi
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}
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if (flags->add_assoc) {
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- rc = filespec_add(stat_buf.st_ino, newcon, pathname, flags);
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+ rc = filespec_add(sb->st_ino, newcon, pathname, flags);
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if (rc < 0) {
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selinux_log(SELINUX_ERROR,
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"filespec_add error: %s\n", pathname);
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- goto out1;
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+ freecon(newcon);
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+ return -1;
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}
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if (rc > 0) {
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/* Already an association and it took precedence. */
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- goto out;
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+ freecon(newcon);
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+ return 0;
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}
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}
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@@ -708,7 +702,7 @@ static int restorecon_sb(const char *pathname, struct rest_flags *flags, bool fi
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selinux_log(SELINUX_INFO, "%s matched by %s\n",
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pathname, newcon);
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- if (fgetfilecon_raw(fd, &curcon) < 0) {
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+ if (lgetfilecon_raw(pathname, &curcon) < 0) {
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if (errno != ENODATA)
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goto err;
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@@ -741,7 +735,7 @@ static int restorecon_sb(const char *pathname, struct rest_flags *flags, bool fi
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}
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if (!flags->nochange) {
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- if (fsetfilecon(fd, newcon) < 0)
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+ if (lsetfilecon(pathname, newcon) < 0)
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goto err;
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updated = true;
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}
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@@ -766,8 +760,6 @@ static int restorecon_sb(const char *pathname, struct rest_flags *flags, bool fi
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out:
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rc = 0;
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out1:
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- if (fd >= 0)
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- close(fd);
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freecon(curcon);
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freecon(newcon);
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return rc;
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@@ -865,6 +857,7 @@ static void *selinux_restorecon_thread(void *arg)
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FTSENT *ftsent;
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int error;
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char ent_path[PATH_MAX];
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+ struct stat ent_st;
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bool first = false;
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if (state->parallel)
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@@ -962,11 +955,11 @@ loop_body:
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/* fall through */
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default:
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strcpy(ent_path, ftsent->fts_path);
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-
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+ ent_st = *ftsent->fts_statp;
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if (state->parallel)
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pthread_mutex_unlock(&state->mutex);
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- error = restorecon_sb(ent_path, &state->flags,
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+ error = restorecon_sb(ent_path, &ent_st, &state->flags,
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first);
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if (state->parallel) {
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@@ -1162,7 +1155,7 @@ static int selinux_restorecon_common(const char *pathname_orig,
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goto cleanup;
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}
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- error = restorecon_sb(pathname, &state.flags, true);
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+ error = restorecon_sb(pathname, &sb, &state.flags, true);
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goto cleanup;
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}
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--
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2.36.1
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