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Manjarres" To: lorenzo.stoakes@oracle.com, gregkh@linuxfoundation.org, Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang Cc: aliceryhl@google.com, stable@vger.kernel.org, "Isaac J. Manjarres" , kernel-team@android.com, Lorenzo Stoakes , Jan Kara , Alexander Viro , Andy Lutomirski , Christian Brauner , "Matthew Wilcox (Oracle)" , Mike Kravetz , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B9F30180008 X-Stat-Signature: 6394rhtu37ezb8e7tf3beybp9hn5pmjn X-Rspam-User: X-HE-Tag: 1753840428-554104 X-HE-Meta: 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 SFxTSOpq 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Lorenzo Stoakes [ Upstream commit 28464bbb2ddc199433383994bcb9600c8034afa1 ] The seal_check_future_write() function is called by shmem_mmap() or hugetlbfs_file_mmap() to disallow any future writable mappings of an memfd sealed this way. The F_SEAL_WRITE flag is not checked here, as that is handled via the mapping->i_mmap_writable mechanism and so any attempt at a mapping would fail before this could be run. However we intend to change this, meaning this check can be performed for F_SEAL_WRITE mappings also. The logic here is equally applicable to both flags, so update this function to accommodate both and rename it accordingly. Link: https://lkml.kernel.org/r/913628168ce6cce77df7d13a63970bae06a526e0.1697116581.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes Reviewed-by: Jan Kara Cc: Alexander Viro Cc: Andy Lutomirski Cc: Christian Brauner Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Mike Kravetz Cc: Muchun Song Signed-off-by: Andrew Morton Cc: stable@vger.kernel.org Signed-off-by: Isaac J. Manjarres --- fs/hugetlbfs/inode.c | 2 +- include/linux/mm.h | 15 ++++++++------- mm/shmem.c | 2 +- 3 files changed, 10 insertions(+), 9 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 9b6004bc96de..c8a5d94561ff 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -148,7 +148,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND; vma->vm_ops = &hugetlb_vm_ops; - ret = seal_check_future_write(info->seals, vma); + ret = seal_check_write(info->seals, vma); if (ret) return ret; diff --git a/include/linux/mm.h b/include/linux/mm.h index 0ec171c6557a..61874611d0e4 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3287,25 +3287,26 @@ static inline void mem_dump_obj(void *object) {} #endif /** - * seal_check_future_write - Check for F_SEAL_FUTURE_WRITE flag and handle it + * seal_check_write - Check for F_SEAL_WRITE or F_SEAL_FUTURE_WRITE flags and + * handle them. * @seals: the seals to check * @vma: the vma to operate on * - * Check whether F_SEAL_FUTURE_WRITE is set; if so, do proper check/handling on - * the vma flags. Return 0 if check pass, or <0 for errors. + * Check whether F_SEAL_WRITE or F_SEAL_FUTURE_WRITE are set; if so, do proper + * check/handling on the vma flags. Return 0 if check pass, or <0 for errors. */ -static inline int seal_check_future_write(int seals, struct vm_area_struct *vma) +static inline int seal_check_write(int seals, struct vm_area_struct *vma) { - if (seals & F_SEAL_FUTURE_WRITE) { + if (seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) { /* * New PROT_WRITE and MAP_SHARED mmaps are not allowed when - * "future write" seal active. + * write seals are active. */ if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE)) return -EPERM; /* - * Since an F_SEAL_FUTURE_WRITE sealed memfd can be mapped as + * Since an F_SEAL_[FUTURE_]WRITE sealed memfd can be mapped as * MAP_SHARED and read-only, take care to not allow mprotect to * revert protections on such mappings. Do this only for shared * mappings. For private mappings, don't need to mask diff --git a/mm/shmem.c b/mm/shmem.c index 431a48e1b90c..06ed84ebdf3b 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2262,7 +2262,7 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma) struct shmem_inode_info *info = SHMEM_I(file_inode(file)); int ret; - ret = seal_check_future_write(info->seals, vma); + ret = seal_check_write(info->seals, vma); if (ret) return ret; -- 2.50.1.552.g942d659e1b-goog