The branch stable/15 has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=052d8f6acf46843bd672f44ff2a09497408eed57
commit 052d8f6acf46843bd672f44ff2a09497408eed57 Author: Olivier Certner <[email protected]> AuthorDate: 2025-08-26 17:01:03 +0000 Commit: Olivier Certner <[email protected]> CommitDate: 2025-09-23 12:02:40 +0000 unix: SCM_CREDS: Restore passing the effective GID cmcred_groups[0] in 'struct cmsgcred' must be the effective GID. Note that the code in unp_addsockcred() filling up 'struct sockcred'/'struct sockcred2' (LOCAL_CREDS/LOCAL_CREDS_PERSISTENT options) was in fact "wrong" before 'cr_gid' was moved out of cr_groups[], in the sense that it would transmit the effective GID twice, both separately as 'sc_egid' and as the first element of 'sc_groups'. It is now exact, so is left unchanged, which causes a difference in output (the effective GID is no more in 'sc_groups', unless it is also a supplementary group) that is unlikely to affect applications in practice. Reviewed by: glebius Fixes: be1f7435ef218b1d ("kern: start tracking cr_gid outside of cr_groups[]") MFC after: 5 days MFC to: stable/15 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D52262 (cherry picked from commit c5e920e49c0cf068da3962688cc60ab514ea1252) --- sys/kern/uipc_usrreq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c index 6138e543fae7..340d84666459 100644 --- a/sys/kern/uipc_usrreq.c +++ b/sys/kern/uipc_usrreq.c @@ -3667,11 +3667,14 @@ unp_internalize(struct mbuf *control, struct mchain *mc, struct thread *td) cmcred->cmcred_uid = td->td_ucred->cr_ruid; cmcred->cmcred_gid = td->td_ucred->cr_rgid; cmcred->cmcred_euid = td->td_ucred->cr_uid; - cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, + _Static_assert(CMGROUP_MAX >= 1, + "Room needed for the effective GID."); + cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups + 1, CMGROUP_MAX); - for (i = 0; i < cmcred->cmcred_ngroups; i++) + cmcred->cmcred_groups[0] = td->td_ucred->cr_gid; + for (i = 1; i < cmcred->cmcred_ngroups; i++) cmcred->cmcred_groups[i] = - td->td_ucred->cr_groups[i]; + td->td_ucred->cr_groups[i - 1]; break; case SCM_RIGHTS:
