[ptxdist] [PATCH 1/2] file: seccomp sandboxing

[ptxdist] [PATCH 1/2] file: seccomp sandboxing

[Clemens Gruber]

Support seccomp sandboxing to reduce the attack surface and enable it by
default. Important for usecases with files from untrusted sources.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
---
 rules/file.in   | 14 +++++++++++++-
 rules/file.make |  2 +-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/rules/file.in b/rules/file.in
index a4e0a7125..3f44cc380 100644
--- a/rules/file.in
+++ b/rules/file.in
@@ -1,10 +1,11 @@
 ## SECTION=shell_and_console
 
-config FILE
+menuconfig FILE
 	tristate
 	select HOST_FILE
 	select ZLIB
 	select GCCLIBS_GCC_S
+	select LIBSECCOMP if FILE_SECCOMP
 	prompt "file"
 	help
 	  The file command is "a file type guesser", that is, a command-line tool
@@ -15,3 +16,14 @@ config FILE
 	  reliable, but requires a bit of I/O.
 	  
 	  http://www.darwinsys.com/file/
+
+if FILE
+
+config FILE_SECCOMP
+	bool
+	default y
+	prompt "enable seccomp sandboxing"
+	help
+	  Enables seccomp sandboxing to reduce the attack surface.
+
+endif
diff --git a/rules/file.make b/rules/file.make
index d60a0b045..bfa39ae76 100644
--- a/rules/file.make
+++ b/rules/file.make
@@ -37,7 +37,7 @@ FILE_CONF_OPT	:= \
 	--enable-elf \
 	--enable-elf-core \
 	--enable-zlib \
-	--disable-libseccomp \
+	--$(call ptx/endis, PTXCONF_FILE_SECCOMP)-libseccomp \
 	--disable-fsect-man5 \
 	$(GLOBAL_LARGE_FILE_OPTION) \
 	--disable-warnings
-- 
2.18.0


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[ptxdist] [PATCH 2/2] file: add upstream seccomp patches

[Clemens Gruber]

Several syscalls are missing in file 5.33. Fix it by pulling in four
upstream patches.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
---
 ...s-newfstatat-is-used-for-stat-ing-th.patch | 56 +++++++++++++++++++
 ...s-add-more-syscalls-for-32-bit-linux.patch | 42 ++++++++++++++
 .../0003-one-more-syscall-for-32-bits.patch   | 29 ++++++++++
 .../0004-Fix-pasto-Clemens-Gruber.patch       | 30 ++++++++++
 patches/file-5.33/series                      |  8 +++
 5 files changed, 165 insertions(+)
 create mode 100644 patches/file-5.33/0001-add-more-syscalls-newfstatat-is-used-for-stat-ing-th.patch
 create mode 100644 patches/file-5.33/0002-PR-5-tobias-add-more-syscalls-for-32-bit-linux.patch
 create mode 100644 patches/file-5.33/0003-one-more-syscall-for-32-bits.patch
 create mode 100644 patches/file-5.33/0004-Fix-pasto-Clemens-Gruber.patch
 create mode 100644 patches/file-5.33/series

diff --git a/patches/file-5.33/0001-add-more-syscalls-newfstatat-is-used-for-stat-ing-th.patch b/patches/file-5.33/0001-add-more-syscalls-newfstatat-is-used-for-stat-ing-th.patch
new file mode 100644
index 000000000..e2f59686d
--- /dev/null
+++ b/patches/file-5.33/0001-add-more-syscalls-newfstatat-is-used-for-stat-ing-th.patch
@@ -0,0 +1,56 @@
+From: Christos Zoulas <christos@zoulas.com>
+Date: Sun, 6 May 2018 16:36:41 +0000
+Subject: [PATCH] add more syscalls; newfstatat is used for stat'ing the magic
+ file, getdents64 is used for getting the magic entries during compilation.
+
+---
+ src/seccomp.c | 15 ++++++++-------
+ 1 file changed, 8 insertions(+), 7 deletions(-)
+
+diff --git a/src/seccomp.c b/src/seccomp.c
+index 7c8a31443b43..481a5624784c 100644
+--- a/src/seccomp.c
++++ b/src/seccomp.c
+@@ -27,7 +27,7 @@
+ #include "file.h"
+ 
+ #ifndef	lint
+-FILE_RCSID("@(#)$File: seccomp.c,v 1.2 2017/11/04 01:14:25 christos Exp $")
++FILE_RCSID("@(#)$File: seccomp.c,v 1.3 2018/05/06 16:36:41 christos Exp $")
+ #endif	/* lint */
+ 
+ #if HAVE_LIBSECCOMP
+@@ -59,12 +59,7 @@ enable_sandbox_basic(void)
+ 	if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1)
+ 		return -1;
+ 
+-#if 0
+-	// prevent escape via ptrace
+-	prctl(PR_SET_DUMPABLE, 0);
+-#endif
+-
+-	if (prctl (PR_SET_DUMPABLE, 0, 0, 0, 0) == -1)
++	if (prctl(PR_SET_DUMPABLE, 0, 0, 0, 0) == -1)
+ 		return -1;
+ 
+ 	// initialize the filter
+@@ -171,6 +166,9 @@ enable_sandbox_full(void)
+ 	ALLOW_RULE(fcntl);  
+ 	ALLOW_RULE(fstat);
+ 	ALLOW_RULE(getdents);
++#ifdef __NR_getdents64
++	ALLOW_RULE(getdents64);
++#endif
+ 	ALLOW_RULE(ioctl);
+ 	ALLOW_RULE(lseek);
+ 	ALLOW_RULE(lstat);
+@@ -178,6 +176,9 @@ enable_sandbox_full(void)
+ 	ALLOW_RULE(mprotect);
+ 	ALLOW_RULE(mremap);
+ 	ALLOW_RULE(munmap);
++#ifdef __NR_newfstatat
++	ALLOW_RULE(newfstatat);
++#endif
+ 	ALLOW_RULE(open);
+ 	ALLOW_RULE(openat);
+ 	ALLOW_RULE(pread64);
diff --git a/patches/file-5.33/0002-PR-5-tobias-add-more-syscalls-for-32-bit-linux.patch b/patches/file-5.33/0002-PR-5-tobias-add-more-syscalls-for-32-bit-linux.patch
new file mode 100644
index 000000000..08e178a8d
--- /dev/null
+++ b/patches/file-5.33/0002-PR-5-tobias-add-more-syscalls-for-32-bit-linux.patch
@@ -0,0 +1,42 @@
+From: Christos Zoulas <christos@zoulas.com>
+Date: Sat, 23 Jun 2018 16:09:11 +0000
+Subject: [PATCH] PR/5: tobias: add more syscalls for 32 bit linux
+
+---
+ src/seccomp.c | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/src/seccomp.c b/src/seccomp.c
+index 481a5624784c..51cf71c4ef6d 100644
+--- a/src/seccomp.c
++++ b/src/seccomp.c
+@@ -27,7 +27,7 @@
+ #include "file.h"
+ 
+ #ifndef	lint
+-FILE_RCSID("@(#)$File: seccomp.c,v 1.3 2018/05/06 16:36:41 christos Exp $")
++FILE_RCSID("@(#)$File: seccomp.c,v 1.4 2018/06/23 16:09:11 christos Exp $")
+ #endif	/* lint */
+ 
+ #if HAVE_LIBSECCOMP
+@@ -164,15 +164,20 @@ enable_sandbox_full(void)
+ 	ALLOW_RULE(exit);
+ 	ALLOW_RULE(exit_group);
+ 	ALLOW_RULE(fcntl);  
++ 	ALLOW_RULE(fcntl64);  
+ 	ALLOW_RULE(fstat);
++ 	ALLOW_RULE(fcntl64);  
+ 	ALLOW_RULE(getdents);
+ #ifdef __NR_getdents64
+ 	ALLOW_RULE(getdents64);
+ #endif
+ 	ALLOW_RULE(ioctl);
+ 	ALLOW_RULE(lseek);
++ 	ALLOW_RULE(_llseek);
+ 	ALLOW_RULE(lstat);
++ 	ALLOW_RULE(lstat64);
+ 	ALLOW_RULE(mmap);
++ 	ALLOW_RULE(mmap2);
+ 	ALLOW_RULE(mprotect);
+ 	ALLOW_RULE(mremap);
+ 	ALLOW_RULE(munmap);
diff --git a/patches/file-5.33/0003-one-more-syscall-for-32-bits.patch b/patches/file-5.33/0003-one-more-syscall-for-32-bits.patch
new file mode 100644
index 000000000..d45cfdac7
--- /dev/null
+++ b/patches/file-5.33/0003-one-more-syscall-for-32-bits.patch
@@ -0,0 +1,29 @@
+From: Christos Zoulas <christos@zoulas.com>
+Date: Sat, 23 Jun 2018 16:19:02 +0000
+Subject: [PATCH] one more syscall for 32 bits
+
+---
+ src/seccomp.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/src/seccomp.c b/src/seccomp.c
+index 51cf71c4ef6d..6da7d658deb9 100644
+--- a/src/seccomp.c
++++ b/src/seccomp.c
+@@ -27,7 +27,7 @@
+ #include "file.h"
+ 
+ #ifndef	lint
+-FILE_RCSID("@(#)$File: seccomp.c,v 1.4 2018/06/23 16:09:11 christos Exp $")
++FILE_RCSID("@(#)$File: seccomp.c,v 1.5 2018/06/23 16:19:02 christos Exp $")
+ #endif	/* lint */
+ 
+ #if HAVE_LIBSECCOMP
+@@ -194,6 +194,7 @@ enable_sandbox_full(void)
+ 	ALLOW_RULE(rt_sigreturn);
+ 	ALLOW_RULE(select);
+ 	ALLOW_RULE(stat);
++	ALLOW_RULE(stat64);
+ 	ALLOW_RULE(sysinfo);
+ 	ALLOW_RULE(unlink);
+ 	ALLOW_RULE(write);
diff --git a/patches/file-5.33/0004-Fix-pasto-Clemens-Gruber.patch b/patches/file-5.33/0004-Fix-pasto-Clemens-Gruber.patch
new file mode 100644
index 000000000..83bdf6d08
--- /dev/null
+++ b/patches/file-5.33/0004-Fix-pasto-Clemens-Gruber.patch
@@ -0,0 +1,30 @@
+From: Christos Zoulas <christos@zoulas.com>
+Date: Tue, 26 Jun 2018 20:29:29 +0000
+Subject: [PATCH] Fix pasto (Clemens Gruber)
+
+---
+ src/seccomp.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/seccomp.c b/src/seccomp.c
+index 6da7d658deb9..a5abb4a159f9 100644
+--- a/src/seccomp.c
++++ b/src/seccomp.c
+@@ -27,7 +27,7 @@
+ #include "file.h"
+ 
+ #ifndef	lint
+-FILE_RCSID("@(#)$File: seccomp.c,v 1.5 2018/06/23 16:19:02 christos Exp $")
++FILE_RCSID("@(#)$File: seccomp.c,v 1.6 2018/06/26 20:29:29 christos Exp $")
+ #endif	/* lint */
+ 
+ #if HAVE_LIBSECCOMP
+@@ -166,7 +166,7 @@ enable_sandbox_full(void)
+ 	ALLOW_RULE(fcntl);  
+  	ALLOW_RULE(fcntl64);  
+ 	ALLOW_RULE(fstat);
+- 	ALLOW_RULE(fcntl64);  
++ 	ALLOW_RULE(fstat64);  
+ 	ALLOW_RULE(getdents);
+ #ifdef __NR_getdents64
+ 	ALLOW_RULE(getdents64);
diff --git a/patches/file-5.33/series b/patches/file-5.33/series
new file mode 100644
index 000000000..7d191a433
--- /dev/null
+++ b/patches/file-5.33/series
@@ -0,0 +1,8 @@
+# generated by git-ptx-patches
+#tag:base --start-number 1
+#tag:upstream --start-number 1
+0001-add-more-syscalls-newfstatat-is-used-for-stat-ing-th.patch
+0002-PR-5-tobias-add-more-syscalls-for-32-bit-linux.patch
+0003-one-more-syscall-for-32-bits.patch
+0004-Fix-pasto-Clemens-Gruber.patch
+# 2af12a2494048da781590d463137b3ca  - git-ptx-patches magic
-- 
2.18.0


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