(slimming up the CC list, I don't think this is too relevant to the wider stable community)
On Fri, Jan 26, 2024 at 01:01:15PM -0800, Guenter Roeck wrote: > On 1/26/24 12:34, Nathan Chancellor wrote: > > On Fri, Jan 26, 2024 at 10:17:23AM -0800, Guenter Roeck wrote: > > > On 1/26/24 09:51, Greg Kroah-Hartman wrote: > > > > On Fri, Jan 26, 2024 at 08:46:42AM -0800, Guenter Roeck wrote: > > > > > On 1/22/24 15:55, Greg Kroah-Hartman wrote: > > > > > > This is the start of the stable review cycle for the 5.10.209 > > > > > > release. > > > > > > There are 286 patches in this series, all will be posted as a > > > > > > response > > > > > > to this one. If anyone has any issues with these being applied, > > > > > > please > > > > > > let me know. > > > > > > > > > > > > Responses should be made by Wed, 24 Jan 2024 23:56:49 +0000. > > > > > > Anything received after that time might be too late. > > > > > > > > > > > [ ... ] > > > > > > > > > > > zhenwei pi <pizhen...@bytedance.com> > > > > > > virtio-crypto: implement RSA algorithm > > > > > > > > > > > > > > > > Curious: Why was this (and its subsequent fixes) backported to > > > > > v5.10.y ? > > > > > It is quite beyond a bug fix. Also, unless I am really missing > > > > > something, > > > > > the series (or at least this patch) was not applied to v5.15.y, so we > > > > > now > > > > > have functionality in v5.10.y which is not in v5.15.y. > > > > > > > > See the commit text, it was a dependency of a later fix and documented > > > > as such. > > > > > > > > Having it in 5.10 and not 5.15 is a bit odd, I agree, so patches are > > > > gladly accepted :) > > > > > > > > > > We reverted the entire series from the merge because it results in a build > > > failure for us. > > > > > > In file included from > > > /home/groeck/src/linux-chromeos/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c:10: > > > In file included from > > > /home/groeck/src/linux-chromeos/include/linux/mpi.h:21: > > > In file included from > > > /home/groeck/src/linux-chromeos/include/linux/scatterlist.h:5: > > > In file included from > > > /home/groeck/src/linux-chromeos/include/linux/string.h:293: > > > /home/groeck/src/linux-chromeos/include/linux/fortify-string.h:512:4: > > > error: call to __read_overflow2_field declared with 'warning' attribute: > > > detected read beyond size of field (2nd parameter); maybe use > > > struct_group()? [-Werror,-Wattribute-warning] > > > __read_overflow2_field(q_size_field, size); > > > > For what it's worth, this is likely self inflicted for chromeos-5.10, > > which carries a revert of commit eaafc590053b ("fortify: Explicitly > > disable Clang support") as commit c19861d34c003 ("CHROMIUM: Revert > > "fortify: Explicitly disable Clang support""). I don't see the series > > that added proper support for clang to fortify in 5.18 that ended with > > commit 281d0c962752 ("fortify: Add Clang support") in that ChromeOS > > branch, so this seems somewhat expected. > > > > That explains that ;-). I don't mind if the patches stay in v5.10.y, > we have them reverted anyway. > > The revert was a pure process issue, as you may see when looking into > commit c19861d34c003, so, yes, I agree that it is self-inflicted damage. > Still, that doesn't explain why the problem exists in 5.18+. > > > > I also see that upstream (starting with 6.1) when trying to build it with > > > clang, > > > so I guess it is one of those bug-for-bug compatibility things. I really > > > have > > > no idea what causes it, or why we don't see the problem when building > > > chromeos-6.1 or chromeos-6.6, but (so far) only with chromeos-5.10 after > > > merging 5.10.209 into it. Making things worse, the problem isn't _always_ > > > seen. Sometimes I can compile the file in 6.1.y without error, sometimes > > > not. > > > I have no idea what triggers the problem. > > > > Have a .config that reproduces it on upstream? I have not personally > > seen this warning in my build matrix nor has our continuous-integration > > matrix (I don't see it in the warning output at the bottom but that > > could have missed something for some reason) in 6.1: > > > > The following command sequence reproduces the problem for me with all stable > branches starting with 5.18.y (plus mainline). > > rm -rf /tmp/crypto-build > mkdir /tmp/crypto-build > make -j CC=clang-15 mrproper >/dev/null 2>&1 > make -j O=/tmp/crypto-build CC=clang-15 allmodconfig >/dev/null 2>&1 > make -j O=/tmp/crypto-build W=1 CC=clang-15 > drivers/crypto/virtio/virtio_crypto_akcipher_algs.o > > I tried clang versions 14, 15, and 16. This is with my home system running > Ubuntu 22.04, no ChromeOS or Google specifics/internals involved. For > clang-15, > the version is > > Ubuntu clang version 15.0.7 > Target: x86_64-pc-linux-gnu > Thread model: posix > InstalledDir: /usr/bin Okay interesting, this warning is hidden behind W=1, which our CI does not test with. Looks like it has been that way since the introduction of these checks in f68f2ff91512 ("fortify: Detect struct member overflows in memcpy() at compile-time"). I think this is a legitimate warning though. It is complaining about the second memcpy() in virtio_crypto_alg_akcipher_init_session(): memcpy(&ctrl->u, para, sizeof(ctrl->u)); where ctrl is: struct virtio_crypto_op_ctrl_req { struct virtio_crypto_ctrl_header header; /* 0 16 */ union { struct virtio_crypto_sym_create_session_req sym_create_session; /* 16 56 */ struct virtio_crypto_hash_create_session_req hash_create_session; /* 16 56 */ struct virtio_crypto_mac_create_session_req mac_create_session; /* 16 56 */ struct virtio_crypto_aead_create_session_req aead_create_session; /* 16 56 */ struct virtio_crypto_akcipher_create_session_req akcipher_create_session; /* 16 56 */ struct virtio_crypto_destroy_session_req destroy_session; /* 16 56 */ __u8 padding[56]; /* 16 56 */ } u; /* 16 56 */ union { struct virtio_crypto_sym_create_session_req sym_create_session; /* 0 56 */ struct virtio_crypto_hash_create_session_req hash_create_session; /* 0 56 */ struct virtio_crypto_mac_create_session_req mac_create_session; /* 0 56 */ struct virtio_crypto_aead_create_session_req aead_create_session; /* 0 56 */ struct virtio_crypto_akcipher_create_session_req akcipher_create_session; /* 0 56 */ struct virtio_crypto_destroy_session_req destroy_session; /* 0 56 */ __u8 padding[56]; /* 0 56 */ }; /* size: 72, cachelines: 2, members: 2 */ /* last cacheline: 8 bytes */ }; (so size and p_size_field should be 56) and the type of the para parameter in virtio_crypto_alg_akcipher_init_session() is 'void *' but the para passed by reference to virtio_crypto_alg_akcipher_init_session() in virtio_crypto_rsa_set_key() has a type of 'struct virtio_crypto_akcipher_session_para': struct virtio_crypto_akcipher_session_para { __le32 algo; /* 0 4 */ __le32 keytype; /* 4 4 */ __le32 keylen; /* 8 4 */ union { struct virtio_crypto_rsa_session_para rsa; /* 12 8 */ struct virtio_crypto_ecdsa_session_para ecdsa; /* 12 8 */ } u; /* 12 8 */ union { struct virtio_crypto_rsa_session_para rsa; /* 0 8 */ struct virtio_crypto_ecdsa_session_para ecdsa; /* 0 8 */ }; /* size: 20, cachelines: 1, members: 4 */ /* last cacheline: 20 bytes */ }; (so q_size_field would be 20 if clang were able to do inlining to see through the 'void *'...?), which would result in the __compiletime_lessthan(q_size_field, size) check succeeding and triggering the warning because 20 < 56, so it does seem like there is an overread of the source buffer here? Adding the maintainers of the driver and subsystem in question. Cheers, Nathan