| Message ID | 20240729113247.1673713-1-vmojzis@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v5] libsemanage: Preserve file context and ownership in policy store | expand |
On Mon, Jul 29, 2024 at 7:33 AM Vit Mojzis <vmojzis@redhat.com> wrote: > > Make sure that file context (all parts) and ownership of > files/directories in policy store does not change no matter which user > and under which context executes policy rebuild. > > Fixes: > # semodule -B > # ls -lZ /etc/selinux/targeted/contexts/files > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 421397 Jul 11 09:57 file_contexts > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 593470 Jul 11 09:57 file_contexts.bin > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 14704 Jul 11 09:57 file_contexts.homedirs > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 20289 Jul 11 09:57 file_contexts.homedirs.bin > > SELinux user changed from system_u to the user used to execute semodule > > # capsh --user=testuser --caps="cap_dac_override,cap_chown+eip" --addamb=cap_dac_override,cap_chown -- -c "semodule -B" > # ls -lZ /etc/selinux/targeted/contexts/files > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 421397 Jul 19 09:10 file_contexts > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 593470 Jul 19 09:10 file_contexts.bin > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 14704 Jul 19 09:10 file_contexts.homedirs > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 20289 Jul 19 09:10 file_contexts.homedirs.bin > > Both file context and ownership changed -- causes remote login > failures and other issues in some scenarios. > > Signed-off-by: Vit Mojzis <vmojzis@redhat.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> > --- > Changes in V5: > - Check return value of fchown and warn user if it fails > > Should I start creating github pull requests for each patch to catch this > type of issue in the future (so that I don't waste your time)? You don't need to create a PR to trigger the GitHub CI testing; just push the change to a branch of your own fork of the selinux repo and it will run the tests for you. > > libsemanage/src/semanage_store.c | 32 ++++++++++++++++++++++++++++++++ > libsemanage/src/semanage_store.h | 1 + > 2 files changed, 33 insertions(+) > > diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c > index 27c5d349..0ac2e5b2 100644 > --- a/libsemanage/src/semanage_store.c > +++ b/libsemanage/src/semanage_store.c > @@ -36,6 +36,7 @@ typedef struct dbase_policydb dbase_t; > #include "database_policydb.h" > #include "handle.h" > > +#include <selinux/restorecon.h> > #include <selinux/selinux.h> > #include <sepol/policydb.h> > #include <sepol/module.h> > @@ -767,6 +768,7 @@ int semanage_copy_file(const char *src, const char *dst, mode_t mode, > if (!retval && rename(tmp, dst) == -1) > return -1; > > + semanage_setfiles(dst); > out: > errno = errsv; > return retval; > @@ -819,6 +821,8 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) > goto cleanup; > } > umask(mask); > + > + semanage_setfiles(dst); > } > > for (i = 0; i < len; i++) { > @@ -837,6 +841,7 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) > goto cleanup; > } > umask(mask); > + semanage_setfiles(path2); > } else if (S_ISREG(sb.st_mode) && flag == 1) { > mask = umask(0077); > if (semanage_copy_file(path, path2, sb.st_mode, > @@ -938,6 +943,7 @@ int semanage_mkdir(semanage_handle_t *sh, const char *path) > > } > umask(mask); > + semanage_setfiles(path); > } > else { > /* check that it really is a directory */ > @@ -1614,16 +1620,19 @@ static int semanage_validate_and_compile_fcontexts(semanage_handle_t * sh) > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC)) != 0) { > goto cleanup; > } > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_BIN)); > > if (sefcontext_compile(sh, > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL)) != 0) { > goto cleanup; > } > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL_BIN)); > > if (sefcontext_compile(sh, > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS)) != 0) { > goto cleanup; > } > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS_BIN)); > > status = 0; > cleanup: > @@ -3018,3 +3027,26 @@ int semanage_nc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len, > > return 0; > } > + > +/* Make sure the file context and ownership of files in the policy > + * store does not change */ > +void semanage_setfiles(const char *path){ > + struct stat sb; > + int fd; > + /* Fix the user and role portions of the context, ignore errors > + * since this is not a critical operation */ > + selinux_restorecon(path, SELINUX_RESTORECON_SET_SPECFILE_CTX | SELINUX_RESTORECON_IGNORE_NOENTRY); > + > + /* Make sure "path" is owned by root */ > + if ((geteuid() != 0 || getegid() != 0) && > + ((fd = open(path, O_RDONLY)) != -1)){ > + /* Skip files with the SUID or SGID bit set -- abuse protection */ > + if ((fstat(fd, &sb) != -1) && > + !(S_ISREG(sb.st_mode) && > + (sb.st_mode & (S_ISUID | S_ISGID))) && > + (fchown(fd, 0, 0) == -1)) > + fprintf(stderr, "Warning! Could not set ownership of %s to root\n", path); > + > + close(fd); > + } > +} > diff --git a/libsemanage/src/semanage_store.h b/libsemanage/src/semanage_store.h > index 1fc77da8..e21dadeb 100644 > --- a/libsemanage/src/semanage_store.h > +++ b/libsemanage/src/semanage_store.h > @@ -124,6 +124,7 @@ int semanage_get_cil_paths(semanage_handle_t * sh, semanage_module_info_t *modin > int semanage_get_active_modules(semanage_handle_t *sh, > semanage_module_info_t **modinfo, int *num_modules); > > +void semanage_setfiles(const char *path); > > /* lock file routines */ > int semanage_get_trans_lock(semanage_handle_t * sh); > -- > 2.43.0 > >
On Mon, Jul 29, 2024 at 7:44 AM Stephen Smalley <stephen.smalley.work@gmail.com> wrote: > > On Mon, Jul 29, 2024 at 7:33 AM Vit Mojzis <vmojzis@redhat.com> wrote: > > > > Make sure that file context (all parts) and ownership of > > files/directories in policy store does not change no matter which user > > and under which context executes policy rebuild. > > > > Fixes: > > # semodule -B > > # ls -lZ /etc/selinux/targeted/contexts/files > > > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 421397 Jul 11 09:57 file_contexts > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 593470 Jul 11 09:57 file_contexts.bin > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 14704 Jul 11 09:57 file_contexts.homedirs > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 20289 Jul 11 09:57 file_contexts.homedirs.bin > > > > SELinux user changed from system_u to the user used to execute semodule > > > > # capsh --user=testuser --caps="cap_dac_override,cap_chown+eip" --addamb=cap_dac_override,cap_chown -- -c "semodule -B" > > # ls -lZ /etc/selinux/targeted/contexts/files > > > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 421397 Jul 19 09:10 file_contexts > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 593470 Jul 19 09:10 file_contexts.bin > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 14704 Jul 19 09:10 file_contexts.homedirs > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 20289 Jul 19 09:10 file_contexts.homedirs.bin > > > > Both file context and ownership changed -- causes remote login > > failures and other issues in some scenarios. > > > > Signed-off-by: Vit Mojzis <vmojzis@redhat.com> > > Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> > > > --- > > Changes in V5: > > - Check return value of fchown and warn user if it fails > > > > Should I start creating github pull requests for each patch to catch this > > type of issue in the future (so that I don't waste your time)? > > You don't need to create a PR to trigger the GitHub CI testing; just > push the change to a branch of your own fork of the selinux repo and > it will run the tests for you. And this patch has also been applied to main. Thanks!
On Mon, 29 Jul 2024 at 13:33, Vit Mojzis <vmojzis@redhat.com> wrote: > > Make sure that file context (all parts) and ownership of > files/directories in policy store does not change no matter which user > and under which context executes policy rebuild. > > Fixes: > # semodule -B > # ls -lZ /etc/selinux/targeted/contexts/files > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 421397 Jul 11 09:57 file_contexts > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 593470 Jul 11 09:57 file_contexts.bin > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 14704 Jul 11 09:57 file_contexts.homedirs > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 20289 Jul 11 09:57 file_contexts.homedirs.bin > > SELinux user changed from system_u to the user used to execute semodule > > # capsh --user=testuser --caps="cap_dac_override,cap_chown+eip" --addamb=cap_dac_override,cap_chown -- -c "semodule -B" > # ls -lZ /etc/selinux/targeted/contexts/files > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 421397 Jul 19 09:10 file_contexts > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 593470 Jul 19 09:10 file_contexts.bin > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 14704 Jul 19 09:10 file_contexts.homedirs > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 20289 Jul 19 09:10 file_contexts.homedirs.bin > > Both file context and ownership changed -- causes remote login > failures and other issues in some scenarios. > > Signed-off-by: Vit Mojzis <vmojzis@redhat.com> > --- > Changes in V5: > - Check return value of fchown and warn user if it fails > > Should I start creating github pull requests for each patch to catch this > type of issue in the future (so that I don't waste your time)? > > libsemanage/src/semanage_store.c | 32 ++++++++++++++++++++++++++++++++ > libsemanage/src/semanage_store.h | 1 + > 2 files changed, 33 insertions(+) > > diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c > index 27c5d349..0ac2e5b2 100644 > --- a/libsemanage/src/semanage_store.c > +++ b/libsemanage/src/semanage_store.c > @@ -36,6 +36,7 @@ typedef struct dbase_policydb dbase_t; > #include "database_policydb.h" > #include "handle.h" > > +#include <selinux/restorecon.h> > #include <selinux/selinux.h> > #include <sepol/policydb.h> > #include <sepol/module.h> > @@ -767,6 +768,7 @@ int semanage_copy_file(const char *src, const char *dst, mode_t mode, > if (!retval && rename(tmp, dst) == -1) > return -1; > > + semanage_setfiles(dst); > out: > errno = errsv; > return retval; > @@ -819,6 +821,8 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) > goto cleanup; > } > umask(mask); > + > + semanage_setfiles(dst); > } > > for (i = 0; i < len; i++) { > @@ -837,6 +841,7 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) > goto cleanup; > } > umask(mask); > + semanage_setfiles(path2); > } else if (S_ISREG(sb.st_mode) && flag == 1) { > mask = umask(0077); > if (semanage_copy_file(path, path2, sb.st_mode, > @@ -938,6 +943,7 @@ int semanage_mkdir(semanage_handle_t *sh, const char *path) > > } > umask(mask); > + semanage_setfiles(path); > } > else { > /* check that it really is a directory */ > @@ -1614,16 +1620,19 @@ static int semanage_validate_and_compile_fcontexts(semanage_handle_t * sh) > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC)) != 0) { > goto cleanup; > } > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_BIN)); > > if (sefcontext_compile(sh, > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL)) != 0) { > goto cleanup; > } > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL_BIN)); > > if (sefcontext_compile(sh, > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS)) != 0) { > goto cleanup; > } > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS_BIN)); > > status = 0; > cleanup: > @@ -3018,3 +3027,26 @@ int semanage_nc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len, > > return 0; > } > + > +/* Make sure the file context and ownership of files in the policy > + * store does not change */ > +void semanage_setfiles(const char *path){ > + struct stat sb; > + int fd; > + /* Fix the user and role portions of the context, ignore errors > + * since this is not a critical operation */ > + selinux_restorecon(path, SELINUX_RESTORECON_SET_SPECFILE_CTX | SELINUX_RESTORECON_IGNORE_NOENTRY); > + > + /* Make sure "path" is owned by root */ > + if ((geteuid() != 0 || getegid() != 0) && I currently do not understand this condition. Doesn't it check that we run *not* as root (in which case fchown(2) will probably fail)? > + ((fd = open(path, O_RDONLY)) != -1)){ > + /* Skip files with the SUID or SGID bit set -- abuse protection */ > + if ((fstat(fd, &sb) != -1) && > + !(S_ISREG(sb.st_mode) && > + (sb.st_mode & (S_ISUID | S_ISGID))) && > + (fchown(fd, 0, 0) == -1)) > + fprintf(stderr, "Warning! Could not set ownership of %s to root\n", path); > + > + close(fd); > + } > +} > diff --git a/libsemanage/src/semanage_store.h b/libsemanage/src/semanage_store.h > index 1fc77da8..e21dadeb 100644 > --- a/libsemanage/src/semanage_store.h > +++ b/libsemanage/src/semanage_store.h > @@ -124,6 +124,7 @@ int semanage_get_cil_paths(semanage_handle_t * sh, semanage_module_info_t *modin > int semanage_get_active_modules(semanage_handle_t *sh, > semanage_module_info_t **modinfo, int *num_modules); > > +void semanage_setfiles(const char *path); > > /* lock file routines */ > int semanage_get_trans_lock(semanage_handle_t * sh); > -- > 2.43.0 > >
On Mon, Jul 29, 2024 at 11:00 AM Christian Göttsche <cgzones@googlemail.com> wrote: > > On Mon, 29 Jul 2024 at 13:33, Vit Mojzis <vmojzis@redhat.com> wrote: > > > > Make sure that file context (all parts) and ownership of > > files/directories in policy store does not change no matter which user > > and under which context executes policy rebuild. > > > > Fixes: > > # semodule -B > > # ls -lZ /etc/selinux/targeted/contexts/files > > > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 421397 Jul 11 09:57 file_contexts > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 593470 Jul 11 09:57 file_contexts.bin > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 14704 Jul 11 09:57 file_contexts.homedirs > > -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 20289 Jul 11 09:57 file_contexts.homedirs.bin > > > > SELinux user changed from system_u to the user used to execute semodule > > > > # capsh --user=testuser --caps="cap_dac_override,cap_chown+eip" --addamb=cap_dac_override,cap_chown -- -c "semodule -B" > > # ls -lZ /etc/selinux/targeted/contexts/files > > > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 421397 Jul 19 09:10 file_contexts > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 593470 Jul 19 09:10 file_contexts.bin > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 14704 Jul 19 09:10 file_contexts.homedirs > > -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 20289 Jul 19 09:10 file_contexts.homedirs.bin > > > > Both file context and ownership changed -- causes remote login > > failures and other issues in some scenarios. > > > > Signed-off-by: Vit Mojzis <vmojzis@redhat.com> > > --- > > Changes in V5: > > - Check return value of fchown and warn user if it fails > > > > Should I start creating github pull requests for each patch to catch this > > type of issue in the future (so that I don't waste your time)? > > > > libsemanage/src/semanage_store.c | 32 ++++++++++++++++++++++++++++++++ > > libsemanage/src/semanage_store.h | 1 + > > 2 files changed, 33 insertions(+) > > > > diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c > > index 27c5d349..0ac2e5b2 100644 > > --- a/libsemanage/src/semanage_store.c > > +++ b/libsemanage/src/semanage_store.c > > @@ -36,6 +36,7 @@ typedef struct dbase_policydb dbase_t; > > #include "database_policydb.h" > > #include "handle.h" > > > > +#include <selinux/restorecon.h> > > #include <selinux/selinux.h> > > #include <sepol/policydb.h> > > #include <sepol/module.h> > > @@ -767,6 +768,7 @@ int semanage_copy_file(const char *src, const char *dst, mode_t mode, > > if (!retval && rename(tmp, dst) == -1) > > return -1; > > > > + semanage_setfiles(dst); > > out: > > errno = errsv; > > return retval; > > @@ -819,6 +821,8 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) > > goto cleanup; > > } > > umask(mask); > > + > > + semanage_setfiles(dst); > > } > > > > for (i = 0; i < len; i++) { > > @@ -837,6 +841,7 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) > > goto cleanup; > > } > > umask(mask); > > + semanage_setfiles(path2); > > } else if (S_ISREG(sb.st_mode) && flag == 1) { > > mask = umask(0077); > > if (semanage_copy_file(path, path2, sb.st_mode, > > @@ -938,6 +943,7 @@ int semanage_mkdir(semanage_handle_t *sh, const char *path) > > > > } > > umask(mask); > > + semanage_setfiles(path); > > } > > else { > > /* check that it really is a directory */ > > @@ -1614,16 +1620,19 @@ static int semanage_validate_and_compile_fcontexts(semanage_handle_t * sh) > > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC)) != 0) { > > goto cleanup; > > } > > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_BIN)); > > > > if (sefcontext_compile(sh, > > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL)) != 0) { > > goto cleanup; > > } > > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL_BIN)); > > > > if (sefcontext_compile(sh, > > semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS)) != 0) { > > goto cleanup; > > } > > + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS_BIN)); > > > > status = 0; > > cleanup: > > @@ -3018,3 +3027,26 @@ int semanage_nc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len, > > > > return 0; > > } > > + > > +/* Make sure the file context and ownership of files in the policy > > + * store does not change */ > > +void semanage_setfiles(const char *path){ > > + struct stat sb; > > + int fd; > > + /* Fix the user and role portions of the context, ignore errors > > + * since this is not a critical operation */ > > + selinux_restorecon(path, SELINUX_RESTORECON_SET_SPECFILE_CTX | SELINUX_RESTORECON_IGNORE_NOENTRY); > > + > > + /* Make sure "path" is owned by root */ > > + if ((geteuid() != 0 || getegid() != 0) && > > I currently do not understand this condition. > Doesn't it check that we run *not* as root (in which case fchown(2) > will probably fail)? See the patch description. He is trying to run it with just capabilities and not as root.
diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c index 27c5d349..0ac2e5b2 100644 --- a/libsemanage/src/semanage_store.c +++ b/libsemanage/src/semanage_store.c @@ -36,6 +36,7 @@ typedef struct dbase_policydb dbase_t; #include "database_policydb.h" #include "handle.h" +#include <selinux/restorecon.h> #include <selinux/selinux.h> #include <sepol/policydb.h> #include <sepol/module.h> @@ -767,6 +768,7 @@ int semanage_copy_file(const char *src, const char *dst, mode_t mode, if (!retval && rename(tmp, dst) == -1) return -1; + semanage_setfiles(dst); out: errno = errsv; return retval; @@ -819,6 +821,8 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) goto cleanup; } umask(mask); + + semanage_setfiles(dst); } for (i = 0; i < len; i++) { @@ -837,6 +841,7 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) goto cleanup; } umask(mask); + semanage_setfiles(path2); } else if (S_ISREG(sb.st_mode) && flag == 1) { mask = umask(0077); if (semanage_copy_file(path, path2, sb.st_mode, @@ -938,6 +943,7 @@ int semanage_mkdir(semanage_handle_t *sh, const char *path) } umask(mask); + semanage_setfiles(path); } else { /* check that it really is a directory */ @@ -1614,16 +1620,19 @@ static int semanage_validate_and_compile_fcontexts(semanage_handle_t * sh) semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC)) != 0) { goto cleanup; } + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_BIN)); if (sefcontext_compile(sh, semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL)) != 0) { goto cleanup; } + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL_BIN)); if (sefcontext_compile(sh, semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS)) != 0) { goto cleanup; } + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS_BIN)); status = 0; cleanup: @@ -3018,3 +3027,26 @@ int semanage_nc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len, return 0; } + +/* Make sure the file context and ownership of files in the policy + * store does not change */ +void semanage_setfiles(const char *path){ + struct stat sb; + int fd; + /* Fix the user and role portions of the context, ignore errors + * since this is not a critical operation */ + selinux_restorecon(path, SELINUX_RESTORECON_SET_SPECFILE_CTX | SELINUX_RESTORECON_IGNORE_NOENTRY); + + /* Make sure "path" is owned by root */ + if ((geteuid() != 0 || getegid() != 0) && + ((fd = open(path, O_RDONLY)) != -1)){ + /* Skip files with the SUID or SGID bit set -- abuse protection */ + if ((fstat(fd, &sb) != -1) && + !(S_ISREG(sb.st_mode) && + (sb.st_mode & (S_ISUID | S_ISGID))) && + (fchown(fd, 0, 0) == -1)) + fprintf(stderr, "Warning! Could not set ownership of %s to root\n", path); + + close(fd); + } +} diff --git a/libsemanage/src/semanage_store.h b/libsemanage/src/semanage_store.h index 1fc77da8..e21dadeb 100644 --- a/libsemanage/src/semanage_store.h +++ b/libsemanage/src/semanage_store.h @@ -124,6 +124,7 @@ int semanage_get_cil_paths(semanage_handle_t * sh, semanage_module_info_t *modin int semanage_get_active_modules(semanage_handle_t *sh, semanage_module_info_t **modinfo, int *num_modules); +void semanage_setfiles(const char *path); /* lock file routines */ int semanage_get_trans_lock(semanage_handle_t * sh);
Make sure that file context (all parts) and ownership of files/directories in policy store does not change no matter which user and under which context executes policy rebuild. Fixes: # semodule -B # ls -lZ /etc/selinux/targeted/contexts/files -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 421397 Jul 11 09:57 file_contexts -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 593470 Jul 11 09:57 file_contexts.bin -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 14704 Jul 11 09:57 file_contexts.homedirs -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 20289 Jul 11 09:57 file_contexts.homedirs.bin SELinux user changed from system_u to the user used to execute semodule # capsh --user=testuser --caps="cap_dac_override,cap_chown+eip" --addamb=cap_dac_override,cap_chown -- -c "semodule -B" # ls -lZ /etc/selinux/targeted/contexts/files -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 421397 Jul 19 09:10 file_contexts -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 593470 Jul 19 09:10 file_contexts.bin -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 14704 Jul 19 09:10 file_contexts.homedirs -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 20289 Jul 19 09:10 file_contexts.homedirs.bin Both file context and ownership changed -- causes remote login failures and other issues in some scenarios. Signed-off-by: Vit Mojzis <vmojzis@redhat.com> --- Changes in V5: - Check return value of fchown and warn user if it fails Should I start creating github pull requests for each patch to catch this type of issue in the future (so that I don't waste your time)? libsemanage/src/semanage_store.c | 32 ++++++++++++++++++++++++++++++++ libsemanage/src/semanage_store.h | 1 + 2 files changed, 33 insertions(+)