| Message ID | 20171121141940.24371-1-plautrba@redhat.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Tue, 2017-11-21 at 15:19 +0100, Petr Lautrbach wrote: > When a calling process uses umask(0) some files in the SELinux module > store can be created to be world writeable. With this patch, > libsemanage > sets umask(0077) before fopen() operations and restores the original > umask value when it's done. > > Fixes: > drwx------. /var/lib/selinux/targeted/active > -rw-rw-rw-. /var/lib/selinux/targeted/active/booleans.local > -rw-rw-rw-. /var/lib/selinux/targeted/active/policy.linked > -rw-rw-rw-. /var/lib/selinux/targeted/active/seusers.local > > drwx------. > /var/lib/selinux/targeted/active/modules/400/permissive_sshd_t > -rw-rw-rw-. > /var/lib/selinux/targeted/active/modules/400/permissive_sshd_t/cil > -rw-rw-rw-. > /var/lib/selinux/targeted/active/modules/400/permissive_sshd_t/lang_e > xt > drwx------. /var/lib/selinux/targeted/active/modules/disabled > -rw-rw-rw-. > /var/lib/selinux/targeted/active/modules/disabled/zosremote > > Signed-off-by: Petr Lautrbach <plautrba@redhat.com> > --- > libsemanage/src/database_file.c | 3 +++ > libsemanage/src/direct_api.c | 15 +++++++++++++++ > libsemanage/src/semanage_store.c | 4 ++++ > 3 files changed, 22 insertions(+) > > diff --git a/libsemanage/src/database_file.c > b/libsemanage/src/database_file.c > index a21b3eeb..d0172e73 100644 > --- a/libsemanage/src/database_file.c > +++ b/libsemanage/src/database_file.c > @@ -119,13 +119,16 @@ static int dbase_file_flush(semanage_handle_t * > handle, dbase_file_t * dbase) > cache_entry_t *ptr; > const char *fname = NULL; > FILE *str = NULL; > + mode_t mask = 0; Why do we need to initialize this here? > > if (!dbase_llist_is_modified(&dbase->llist)) > return STATUS_SUCCESS; > > fname = dbase->path[handle->is_in_transaction]; > > + mask = umask(0077); > str = fopen(fname, "w"); > + umask(mask); > if (!str) { > ERR(handle, "could not open %s for writing: %s", > fname, strerror(errno)); > diff --git a/libsemanage/src/direct_api.c > b/libsemanage/src/direct_api.c > index 00ad8201..46072f92 100644 > --- a/libsemanage/src/direct_api.c > +++ b/libsemanage/src/direct_api.c > @@ -1176,6 +1176,7 @@ static int > semanage_direct_commit(semanage_handle_t * sh) > sepol_policydb_t *out = NULL; > struct cil_db *cildb = NULL; > semanage_module_info_t *modinfos = NULL; > + mode_t mask = 0; Why do we need to initialize mask here? > > int do_rebuild, do_write_kernel, do_install; > int fcontexts_modified, ports_modified, seusers_modified, > @@ -1212,6 +1213,8 @@ static int > semanage_direct_commit(semanage_handle_t * sh) > /* Rebuild if explicitly requested or any module changes > occurred. */ > do_rebuild = sh->do_rebuild | sh->modules_modified; > > + mask = umask(0077); > + > /* Create or remove the disable_dontaudit flag file. */ > path = semanage_path(SEMANAGE_TMP, > SEMANAGE_DISABLE_DONTAUDIT); > if (access(path, F_OK) == 0) > @@ -1645,6 +1648,10 @@ cleanup: > semanage_remove_directory(semanage_final_path > (SEMANAGE_FINAL_TMP, > SEMANAGE_FINAL_TOPLEVEL)); > + if (mask) { > + umask(mask); > + } Why is this conditional? > + > return retval; > } > > @@ -2016,6 +2023,7 @@ static int > semanage_direct_set_enabled(semanage_handle_t *sh, > const char *path = NULL; > FILE *fp = NULL; > semanage_module_info_t *modinfo = NULL; > + mode_t mask = 0; Ditto > > /* check transaction */ > if (!sh->is_in_transaction) { > @@ -2076,7 +2084,9 @@ static int > semanage_direct_set_enabled(semanage_handle_t *sh, > > switch (enabled) { > case 0: /* disable the module */ > + mask = umask(0077); > fp = fopen(fn, "w"); > + umask(mask); > > if (fp == NULL) { > ERR(sh, > @@ -2722,7 +2732,9 @@ static int > semanage_direct_install_info(semanage_handle_t *sh, > int type; > > char path[PATH_MAX]; > + mode_t mask = 0; No need to initialize this here. > > + mask = umask(0077); And this should go after local variable declarations or get folded into the declaration above. > semanage_module_info_t *higher_info = NULL; > semanage_module_key_t higher_key; > ret = semanage_module_key_init(sh, &higher_key); > @@ -2834,6 +2846,9 @@ cleanup: > semanage_module_info_destroy(sh, higher_info); > free(higher_info); > > + if (mask) { > + umask(mask); > + } Why conditional? > return status; > } > > diff --git a/libsemanage/src/semanage_store.c > b/libsemanage/src/semanage_store.c > index 63c80b04..74fbb677 100644 > --- a/libsemanage/src/semanage_store.c > +++ b/libsemanage/src/semanage_store.c > @@ -2099,11 +2099,13 @@ int semanage_write_policydb(semanage_handle_t > * sh, sepol_policydb_t * out, > const char *kernel_filename = NULL; > struct sepol_policy_file *pf = NULL; > FILE *outfile = NULL; > + mode_t mask = 0; > > if ((kernel_filename = > semanage_path(SEMANAGE_TMP, file)) == NULL) { > goto cleanup; > } > + mask = umask(0077); Just move this before the first goto cleanup and then you don't need to initialize mask or make the test below conditional. > if ((outfile = fopen(kernel_filename, "wb")) == NULL) { > ERR(sh, "Could not open kernel policy %s for > writing.", > kernel_filename); > @@ -2127,6 +2129,8 @@ int semanage_write_policydb(semanage_handle_t * > sh, sepol_policydb_t * out, > if (outfile != NULL) { > fclose(outfile); > } > + if (mask != 0) > + umask(mask); > sepol_policy_file_free(pf); > return retval; > }
diff --git a/libsemanage/src/database_file.c b/libsemanage/src/database_file.c index a21b3eeb..d0172e73 100644 --- a/libsemanage/src/database_file.c +++ b/libsemanage/src/database_file.c @@ -119,13 +119,16 @@ static int dbase_file_flush(semanage_handle_t * handle, dbase_file_t * dbase) cache_entry_t *ptr; const char *fname = NULL; FILE *str = NULL; + mode_t mask = 0; if (!dbase_llist_is_modified(&dbase->llist)) return STATUS_SUCCESS; fname = dbase->path[handle->is_in_transaction]; + mask = umask(0077); str = fopen(fname, "w"); + umask(mask); if (!str) { ERR(handle, "could not open %s for writing: %s", fname, strerror(errno)); diff --git a/libsemanage/src/direct_api.c b/libsemanage/src/direct_api.c index 00ad8201..46072f92 100644 --- a/libsemanage/src/direct_api.c +++ b/libsemanage/src/direct_api.c @@ -1176,6 +1176,7 @@ static int semanage_direct_commit(semanage_handle_t * sh) sepol_policydb_t *out = NULL; struct cil_db *cildb = NULL; semanage_module_info_t *modinfos = NULL; + mode_t mask = 0; int do_rebuild, do_write_kernel, do_install; int fcontexts_modified, ports_modified, seusers_modified, @@ -1212,6 +1213,8 @@ static int semanage_direct_commit(semanage_handle_t * sh) /* Rebuild if explicitly requested or any module changes occurred. */ do_rebuild = sh->do_rebuild | sh->modules_modified; + mask = umask(0077); + /* Create or remove the disable_dontaudit flag file. */ path = semanage_path(SEMANAGE_TMP, SEMANAGE_DISABLE_DONTAUDIT); if (access(path, F_OK) == 0) @@ -1645,6 +1648,10 @@ cleanup: semanage_remove_directory(semanage_final_path (SEMANAGE_FINAL_TMP, SEMANAGE_FINAL_TOPLEVEL)); + if (mask) { + umask(mask); + } + return retval; } @@ -2016,6 +2023,7 @@ static int semanage_direct_set_enabled(semanage_handle_t *sh, const char *path = NULL; FILE *fp = NULL; semanage_module_info_t *modinfo = NULL; + mode_t mask = 0; /* check transaction */ if (!sh->is_in_transaction) { @@ -2076,7 +2084,9 @@ static int semanage_direct_set_enabled(semanage_handle_t *sh, switch (enabled) { case 0: /* disable the module */ + mask = umask(0077); fp = fopen(fn, "w"); + umask(mask); if (fp == NULL) { ERR(sh, @@ -2722,7 +2732,9 @@ static int semanage_direct_install_info(semanage_handle_t *sh, int type; char path[PATH_MAX]; + mode_t mask = 0; + mask = umask(0077); semanage_module_info_t *higher_info = NULL; semanage_module_key_t higher_key; ret = semanage_module_key_init(sh, &higher_key); @@ -2834,6 +2846,9 @@ cleanup: semanage_module_info_destroy(sh, higher_info); free(higher_info); + if (mask) { + umask(mask); + } return status; } diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c index 63c80b04..74fbb677 100644 --- a/libsemanage/src/semanage_store.c +++ b/libsemanage/src/semanage_store.c @@ -2099,11 +2099,13 @@ int semanage_write_policydb(semanage_handle_t * sh, sepol_policydb_t * out, const char *kernel_filename = NULL; struct sepol_policy_file *pf = NULL; FILE *outfile = NULL; + mode_t mask = 0; if ((kernel_filename = semanage_path(SEMANAGE_TMP, file)) == NULL) { goto cleanup; } + mask = umask(0077); if ((outfile = fopen(kernel_filename, "wb")) == NULL) { ERR(sh, "Could not open kernel policy %s for writing.", kernel_filename); @@ -2127,6 +2129,8 @@ int semanage_write_policydb(semanage_handle_t * sh, sepol_policydb_t * out, if (outfile != NULL) { fclose(outfile); } + if (mask != 0) + umask(mask); sepol_policy_file_free(pf); return retval; }
When a calling process uses umask(0) some files in the SELinux module store can be created to be world writeable. With this patch, libsemanage sets umask(0077) before fopen() operations and restores the original umask value when it's done. Fixes: drwx------. /var/lib/selinux/targeted/active -rw-rw-rw-. /var/lib/selinux/targeted/active/booleans.local -rw-rw-rw-. /var/lib/selinux/targeted/active/policy.linked -rw-rw-rw-. /var/lib/selinux/targeted/active/seusers.local drwx------. /var/lib/selinux/targeted/active/modules/400/permissive_sshd_t -rw-rw-rw-. /var/lib/selinux/targeted/active/modules/400/permissive_sshd_t/cil -rw-rw-rw-. /var/lib/selinux/targeted/active/modules/400/permissive_sshd_t/lang_ext drwx------. /var/lib/selinux/targeted/active/modules/disabled -rw-rw-rw-. /var/lib/selinux/targeted/active/modules/disabled/zosremote Signed-off-by: Petr Lautrbach <plautrba@redhat.com> --- libsemanage/src/database_file.c | 3 +++ libsemanage/src/direct_api.c | 15 +++++++++++++++ libsemanage/src/semanage_store.c | 4 ++++ 3 files changed, 22 insertions(+)