** Description changed: SRU Justification: ================== [Impact] * zlib: compressBound() returns an incorrect result on IBM z15 hardware. * Passing the result of compressBound() to compress() results - in an error code. + in an error code. * This is because compressBound() is not adjusted for DFLTCC. [Fix] * Adjust compressBound() for DFLTCC like it's already done - for deflateBound(). + for deflateBound(). * Since zlib project does not accept patches at the moment, - the fix has been integrated into the DFLTCC pull request: - https://github.com/madler/zlib/pull/410 - The commitid is b25781e735363e04f6c56e21431c47e4afc50b17. + the fix has been integrated into the DFLTCC pull request: + https://github.com/madler/zlib/pull/410 + The commitid is b25781e735363e04f6c56e21431c47e4afc50b17. * The fix extracted out of the above is: - https://launchpadlibrarian.net/589857296/debdiff_zlib_1.2.11.dfsg-2ubuntu7_to_zlib_1.2.11.dfsg-2ubuntu8_jammy.diff + https://launchpadlibrarian.net/589857296/debdiff_zlib_1.2.11.dfsg-2ubuntu7_to_zlib_1.2.11.dfsg-2ubuntu8_jammy.diff [Test Plan] * An IBM z15 system (LPAR, z/VM guest or KVM virtual machine) - with Ubuntu Server 21.10 (or 22.04). + with Ubuntu Server 21.10 (or 22.04). * A test can be done based on the following C test program: - #include <assert.h> - #include <stdlib.h> - #include <zlib.h> - int main() { - Bytef in_buf[128], out_buf[1024]; - for (size_t i = 0; i < sizeof(in_buf); i++) - in_buf[i] = rand(); - uLongf dest_len = compressBound(sizeof(in_buf)); - assert(dest_len <= sizeof(out_buf)); - int ret = compress(out_buf, &dest_len, - in_buf, sizeof(in_buf)); - assert(ret == Z_OK); - } + #include <assert.h> + #include <stdlib.h> + #include <zlib.h> + int main() { + Bytef in_buf[128], out_buf[1024]; + for (size_t i = 0; i < sizeof(in_buf); i++) + in_buf[i] = rand(); + uLongf dest_len = compressBound(sizeof(in_buf)); + assert(dest_len <= sizeof(out_buf)); + int ret = compress(out_buf, &dest_len, + in_buf, sizeof(in_buf)); + assert(ret == Z_OK); + } * The test needs to be done by IBM, due to the requirements - for the special z15 hardware. + for the special z15 hardware. + + * A successful test was just completed, based on the version in jammy- + proposed, which is at the same code level that the impish version this + SRU is targeted for. [Where problems could occur] * If the adjustment of compressBound() for DFLTCC is done - erroneously the issue can still be present or in worst case - even affect Z systems other than z15 only. - - * The crc table can be broken, in case the endian detection - or the register initialization is done wrong. + erroneously the issue can still be present or in worst case + even affect Z systems other than z15 only. * The compression can become errorneous with the new changes, - e.g. in compressBound. + e.g. in compressBound. * Mistakes in dfltcc_free_window OF and especially DEFLATE_BOUND_COMPLEN, - (incl. the bit definitions), may cause various and unforseen defects. + (incl. the bit definitions), may cause various and unforseen defects. * Any build time issues that might have been introduced by this patch - can be identified by a test build; this was done and is available here: - https://launchpad.net/~fheimes/+archive/ubuntu/lp1961427 + can be identified by a test build; this was done and is available here: + https://launchpad.net/~fheimes/+archive/ubuntu/lp1961427 [Other Info] * Only impish and jammy are affected. __________ Description: zlib: compressBound() returns an incorrect result on z15 Symptom: Passing the result of compressBound() to compress() results in an error code. Problem: compressBound() is not adjusted for DFLTCC. Solution: Adjust compressBound() for DFLTCC like it's already done for deflateBound(). Since zlib project does not accept patches at the moment, the fix has been integrated into the DFLTCC pull request: https://github.com/madler/zlib/pull/410 The commitid is b25781e735363e04f6c56e21431c47e4afc50b17. Reproduction: z15 only: #include <assert.h> #include <stdlib.h> #include <zlib.h> int main() { Bytef in_buf[128], out_buf[1024]; for (size_t i = 0; i < sizeof(in_buf); i++) in_buf[i] = rand(); uLongf dest_len = compressBound(sizeof(in_buf)); assert(dest_len <= sizeof(out_buf)); int ret = compress(out_buf, &dest_len, in_buf, sizeof(in_buf)); assert(ret == Z_OK); }
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1961427 Title: zlib: compressBound() returns an incorrect result on z15 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1961427/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
