Commit c26d9f6287154774bea6dcea1cea4d1cafaed45c | zig

author	LeRoyce Pearson <contact@leroycepearson.dev> 2022-07-17 16:01:22-06:00
committer	Andrew Kelley <andrew@ziglang.org> 2022-07-19 14:01:35-04:00
log	c26d9f6287154774bea6dcea1cea4d1cafaed45c
tree	15fbf869b27e325095e9f8aa989bdc69a255bc4d
parent	b93a38860d58135072f8a1d7f6258175aa74e0fa

Read dynstr starting at rpath offset

Since we know the offset, we may as well read starting there. Still expects
rpath to fit in 4096 bytes; that might be worth fixing in the future.

Fixes issue #12112

1 files changed, 9 insertions(+), 4 deletions(-)

lib
- std
  - zig
    system
    NativeTargetInfo.zig

lib/std/zig/system/NativeTargetInfo.zig+9-4

 @@ -653,12 +653,17 @@ pub fn abiAndDynamicLinkerFromFile(
             } else null;
             if (dynstr) |ds| {
-                const strtab_len = std.math.min(ds.size, strtab_buf.len);
-                const strtab_read_len = try preadMin(file, &strtab_buf, ds.offset, strtab_len);
-                const strtab = strtab_buf[0..strtab_read_len];
                 // TODO this pointer cast should not be necessary
                 const rpoff_usize = std.math.cast(usize, rpoff) orelse return error.InvalidElfFile;
-                const rpath_list = mem.sliceTo(std.meta.assumeSentinel(strtab[rpoff_usize..].ptr, 0), 0);
+                if (rpoff_usize > ds.size) return error.InvalidElfFile;
+                const rpoff_file = ds.offset + rpoff_usize;
+                const rp_max_size = ds.size - rpoff_usize;
+                const strtab_len = std.math.min(rp_max_size, strtab_buf.len);
+                const strtab_read_len = try preadMin(file, &strtab_buf, rpoff_file, strtab_len);
+                const strtab = strtab_buf[0..strtab_read_len];
+                const rpath_list = mem.sliceTo(std.meta.assumeSentinel(strtab.ptr, 0), 0);
                 var it = mem.tokenize(u8, rpath_list, ":");
                 while (it.next()) |rpath| {
                     var dir = fs.cwd().openDir(rpath, .{}) catch |err| switch (err) {