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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-Queue-Id: 3E04E140007 X-Stat-Signature: ojcqctoxzyog1yh8p445t86ifg1kcsxd X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1753840379-803744 X-HE-Meta: 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 K9mKUPu9 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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 330729445d8a..d4b2a199cb9d 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -136,7 +136,7 @@ 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 b1509be77efb..fcd61558ebcb 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3526,25 +3526,26 @@ 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 2e6b7db7f14b..2034b9b3fb71 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2302,7 +2302,7 @@ 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