Port a fix for CVE-2025-58183 by mtrmac · Pull Request #85 · vbatts/tar-split (original) (raw)

Sparse files in tar archives contain only the non-zero components of the file. There are several different encodings for sparse files. When reading GNU tar pax 1.0 sparse files, archive/tar did not set a limit on the size of the sparse region data. A malicious archive containing a large number of sparse blocks could cause archive/tar to read an unbounded amount of data from the archive into memory.

Since a malicious input can be highly compressable, a small compressed input could cause very large allocations.

Cap the size of the sparse block data to the same limit used for PAX headers (1 MiB).

Thanks to Harshit Gupta (Mr HAX) (https://www.linkedin.com/in/iam-harshit-gupta/) for reporting this issue.

Fixes CVE-2025-58183 For #75677 Fixes #75711

Change-Id: I70b907b584a7b8676df8a149a1db728ae681a770 Reviewed-on: https://go-internal-review.googlesource.com/c/go/+/2800 Reviewed-by: Roland Shoemaker bracewell@google.com Reviewed-by: Nicholas Husin husin@google.com Reviewed-on: https://go-internal-review.googlesource.com/c/go/+/2987 Reviewed-by: Damien Neil dneil@google.com Reviewed-on: https://go-review.googlesource.com/c/go/+/709852 TryBot-Bypass: Michael Pratt mpratt@google.com Reviewed-by: Carlos Amedee carlos@golang.org Auto-Submit: Michael Pratt mpratt@google.com

Signed-off-by: Miloslav Trmač mitr@redhat.com

approved these changes Oct 14, 2025

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