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| author | Lasse Collin <lasse.collin@tukaani.org> | 2024-02-17 23:07:35 +0200 |
|---|---|---|
| committer | Lasse Collin <lasse.collin@tukaani.org> | 2024-02-17 23:07:35 +0200 |
| commit | 02e3505991233901575b7eabc06b2c6c62a96899 (patch) | |
| tree | f3d8729f9fc5655bbc870b377510b17034d13e56 /src | |
| parent | xz: Move sandboxing code to sandbox.c and improve Landlock sandbox. (diff) | |
| download | xz-02e3505991233901575b7eabc06b2c6c62a96899.tar.xz | |
xz: Support Landlock ABI version 4.
Linux 6.7 added support for ABI version 4 which restricts
TCP connections which xz won't need and thus those can be
forbidden now. Since the ABI version is handled at runtime,
supporting version 4 won't cause any compatibility issues.
Note that new enough kernel headers are required to get
version 4 support enabled at build time.
Diffstat (limited to '')
| -rw-r--r-- | src/xz/sandbox.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/src/xz/sandbox.c b/src/xz/sandbox.c index 2c40db71..8a2c115c 100644 --- a/src/xz/sandbox.c +++ b/src/xz/sandbox.c @@ -107,8 +107,18 @@ sandbox_enable_strict_if_allowed(int src_fd lzma_attribute((__unused__)), #include <sys/prctl.h> -// Highest Landlock ABI version supported by this file -#define LANDLOCK_ABI_MAX 3 +// Highest Landlock ABI version supported by this file: +// - For ABI versions 1-3 we don't need anything from <linux/landlock.h> +// that isn't part of version 1. +// - For ABI version 4 we need the larger struct landlock_ruleset_attr +// with the handled_access_net member. That is bundled with the macros +// LANDLOCK_ACCESS_NET_BIND_TCP and LANDLOCK_ACCESS_NET_CONNECT_TCP. +#ifdef LANDLOCK_ACCESS_NET_BIND_TCP +# define LANDLOCK_ABI_MAX 4 +#else +# define LANDLOCK_ABI_MAX 3 +#endif + /// Landlock ABI version supported by the kernel static int landlock_abi; @@ -142,10 +152,15 @@ enable_landlock(uint64_t required_rights) // // This makes it simple to set the mask based on the ABI // version and we don't need to care which flags are #defined - // in the installed <linux/landlock.h>. + // in the installed <linux/landlock.h> for ABI versions 1-3. const struct landlock_ruleset_attr attr = { - .handled_access_fs = ((1ULL << (12 + landlock_abi)) - 1) - & ~required_rights, + .handled_access_fs = ~required_rights + & ((1ULL << (12 + my_min(3, landlock_abi))) - 1), +#if LANDLOCK_ABI_MAX >= 4 + .handled_access_net = landlock_abi < 4 ? 0 : + (LANDLOCK_ACCESS_NET_BIND_TCP + | LANDLOCK_ACCESS_NET_CONNECT_TCP), +#endif }; const int ruleset_fd = syscall(SYS_landlock_create_ruleset, |