[ Sasha's backport helper bot ]
Hi,
✅ All tests passed successfully. No issues detected. No action required from the submitter.
The upstream commit SHA1 provided is correct: bc27c52eea189e8f7492d40739b7746d67b65beb
WARNING: Author mismatch between patch and upstream commit: Backport author: David Sauerweindssauerw@amazon.de Commit author: Andrii Nakryikoandrii@kernel.org
Status in newer kernel trees: 6.14.y | Present (exact SHA1) 6.13.y | Present (different SHA1: 271e49f8a58e) 6.12.y | Present (different SHA1: d95607a5f2f9) 6.6.y | Present (different SHA1: 29cfda62ab4d)
Note: The patch differs from the upstream commit: --- 1: bc27c52eea189 ! 1: dd13352656776 bpf: avoid holding freeze_mutex during mmap operation @@ Metadata ## Commit message ## bpf: avoid holding freeze_mutex during mmap operation
+ [ Upstream commit bc27c52eea189e8f7492d40739b7746d67b65beb ] + We use map->freeze_mutex to prevent races between map_freeze() and memory mapping BPF map contents with writable permissions. The way we naively do this means we'll hold freeze_mutex for entire duration of all @@ Commit message Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/r/20250129012246.1515826-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org + Signed-off-by: Sasha Levin sashal@kernel.org + Signed-off-by: David Sauerwein dssauerw@amazon.de
## kernel/bpf/syscall.c ## @@ kernel/bpf/syscall.c: static const struct vm_operations_struct bpf_map_default_vmops = { @@ kernel/bpf/syscall.c: static const struct vm_operations_struct bpf_map_default_v - int err; + int err = 0;
- if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) - return -ENOTSUPP; + if (!map->ops->map_mmap || map_value_has_spin_lock(map) || + map_value_has_timer(map) || map_value_has_kptrs(map)) @@ kernel/bpf/syscall.c: static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) err = -EACCES; goto out; @@ kernel/bpf/syscall.c: static int bpf_map_mmap(struct file *filp, struct vm_area_ /* set default open/close callbacks */ vma->vm_ops = &bpf_map_default_vmops; @@ kernel/bpf/syscall.c: static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) - vm_flags_clear(vma, VM_MAYWRITE); + vma->vm_flags &= ~VM_MAYWRITE;
err = map->ops->map_mmap(map, vma); - if (err) @@ kernel/bpf/syscall.c: static int bpf_map_mmap(struct file *filp, struct vm_area_ + bpf_map_write_active_dec(map); + }
-- if (vma->vm_flags & VM_WRITE) +- if (vma->vm_flags & VM_MAYWRITE) - bpf_map_write_active_inc(map); -out: - mutex_unlock(&map->freeze_mutex); ---
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | stable/linux-6.1.y | Success | Success |