kernel/linux.git, branch v6.6.139

Linux 6.6.139

2026-05-15T12:50:29+00:00

Signed-off-by: Greg Kroah-Hartman

x86/CPU/AMD: Prevent improper isolation of shared resources in Zen2's op cache

2026-05-15T12:50:29+00:00

commit c21b90f77687075115d989e53a8ec5e2bb427ab1 upstream. Make sure resources are not improperly shared in the op cache and cause instruction corruption this way. Signed-off-by: Prathyushi Nangia Co-developed-by: Borislav Petkov (AMD) Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

ptrace: slightly saner 'get_dumpable()' logic

2026-05-15T12:50:29+00:00

commit 31e62c2ebbfdc3fe3dbdf5e02c92a9dc67087a3a upstream. The 'dumpability' of a task is fundamentally about the memory image of the task - the concept comes from whether it can core dump or not - and makes no sense when you don't have an associated mm. And almost all users do in fact use it only for the case where the task has a mm pointer. But we have one odd special case: ptrace_may_access() uses 'dumpable' to check various other things entirely independently of the MM (typically explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for threads that no longer have a VM (and maybe never did, like most kernel threads). It's not what this flag was designed for, but it is what it is. The ptrace code does check that the uid/gid matches, so you do have to be uid-0 to see kernel thread details, but this means that the traditional "drop capabilities" model doesn't make any difference for this all. Make it all make a *bit* more sense by saying that if you don't have a MM pointer, we'll use a cached "last dumpability" flag if the thread ever had a MM (it will be zero for kernel threads since it is never set), and require a proper CAP_SYS_PTRACE capability to override. Reported-by: Qualys Security Advisory Cc: Oleg Nesterov Cc: Kees Cook Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Linux 6.6.138

2026-05-08T06:38:20+00:00

Signed-off-by: Greg Kroah-Hartman

xfrm: esp: avoid in-place decrypt on shared skb frags

2026-05-08T06:38:20+00:00

commit f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 upstream. MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data(). Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Fixes: 7da0dde68486 ("ip, udp: Support MSG_SPLICE_PAGES") Fixes: 6d8192bd69bb ("ip6, udp6: Support MSG_SPLICE_PAGES") Reported-by: Hyunwoo Kim Reported-by: Kuan-Ting Chen Tested-by: Hyunwoo Kim Cc: stable@vger.kernel.org Signed-off-by: Kuan-Ting Chen Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman

Linux 6.6.137

2026-04-30T09:17:22+00:00

Signed-off-by: Greg Kroah-Hartman

Buffer overflow in drivers/xen/sys-hypervisor.c

2026-04-30T09:17:21+00:00

commit 27fdbab4221b375de54bf91919798d88520c6e28 upstream. The build id returned by HYPERVISOR_xen_version(XENVER_build_id) is neither NUL terminated nor a string. The first causes a buffer overflow as sprintf in buildid_show will read and copy till it finds a NUL. 00000000 f4 91 51 f4 dd 38 9e 9d 65 47 52 eb 10 71 db 50 |..Q..8..eGR..q.P| 00000010 b9 a8 01 42 6f 2e 32 |...Bo.2| 00000017 So use a memcpy instead of sprintf to have the correct value: 00000000 f4 91 51 f4 dd 00 9e 9d 65 47 52 eb 10 71 db 50 |..Q.....eGR..q.P| 00000010 b9 a8 01 42 |...B| 00000014 (the above have a hack to embed a zero inside and check it's returned correctly). This is XSA-485 / CVE-2026-31786 Fixes: 84b7625728ea ("xen: add sysfs node for hypervisor build id") Signed-off-by: Frediano Ziglio Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

xen/privcmd: fix double free via VMA splitting

2026-04-30T09:17:21+00:00

commit 24daca4fc07f3ff8cd0e3f629cd982187f48436a upstream. privcmd_vm_ops defines .close (privcmd_close), but neither .may_split nor .open. When userspace does a partial munmap() on a privcmd mapping, the kernel splits the VMA via __split_vma(). Since may_split is NULL, the split is allowed. vm_area_dup() copies vm_private_data (a pages array allocated in alloc_empty_pages()) into the new VMA without any fixup, because there is no .open callback. Both VMAs now point to the same pages array. When the unmapped portion is closed, privcmd_close() calls: - xen_unmap_domain_gfn_range() - xen_free_unpopulated_pages() - kvfree(pages) The surviving VMA still holds the dangling pointer. When it is later destroyed, the same sequence runs again, which leads to a double free. Fix this issue by adding a .may_split callback denying the VMA split. This is XSA-487 / CVE-2026-31787 Fixes: d71f513985c2 ("xen: privcmd: support autotranslated physmap guests.") Reported-by: Atharva Vartak Suggested-by: Atharva Vartak Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich Signed-off-by: Greg Kroah-Hartman

crypto: af_alg - Fix page reassignment overflow in af_alg_pull_tsgl

2026-04-30T09:17:21+00:00

commit 31d00156e50ecad37f2cb6cbf04aaa9a260505ef upstream. When page reassignment was added to af_alg_pull_tsgl the original loop wasn't updated so it may try to reassign one more page than necessary. Add the check to the reassignment so that this does not happen. Also update the comment which still refers to the obsolete offset argument. Reported-by: syzbot+d23888375c2737c17ba5@syzkaller.appspotmail.com Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management") Signed-off-by: Herbert Xu Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman

crypto: authencesn - Fix src offset when decrypting in-place

2026-04-30T09:17:21+00:00

commit 1f48ad3b19a9dfc947868edda0bb8e48e5b5a8fa upstream. The src SG list offset wasn't set properly when decrypting in-place, fix it. Reported-by: Wolfgang Walter Fixes: e02494114ebf ("crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption") Signed-off-by: Herbert Xu Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman