diff options
| -rw-r--r-- | io_jail/src/lib.rs | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/io_jail/src/lib.rs b/io_jail/src/lib.rs index a927cdb..7a12307 100644 --- a/io_jail/src/lib.rs +++ b/io_jail/src/lib.rs @@ -68,6 +68,8 @@ pub enum Error { PreservingFd(i32), /// Program size is too large ProgramTooLarge, + /// Alignment of file should be divisible by the alignment of sock_filter. + WrongProgramAlignment, /// File size should be non-zero and a multiple of sock_filter WrongProgramSize, } @@ -148,6 +150,10 @@ impl Display for Error { ProcFd(s) => write!(f, "an entry in /proc/self/fd is not an integer: {}", s), PreservingFd(e) => write!(f, "fork failed in minijail_preserve_fd with error {}", e), ProgramTooLarge => write!(f, "bpf program is too large (max 64K instructions)"), + WrongProgramAlignment => write!( + f, + "the alignment of bpf file was not a multiple of that of sock_filter" + ), WrongProgramSize => write!(f, "bpf file was empty or not a multiple of sock_filter"), } } @@ -287,6 +293,13 @@ impl Minijail { if count > (!0 as u16) as usize { return Err(Error::ProgramTooLarge); } + if buffer.as_ptr() as usize % std::mem::align_of::<sock_filter>() != 0 { + return Err(Error::WrongProgramAlignment); + } + + // Safe cast because we checked that the buffer address is divisible by the alignment of + // sock_filter. + #[allow(clippy::cast_ptr_alignment)] let header = sock_fprog { len: count as c_ushort, filter: buffer.as_ptr() as *mut sock_filter, |