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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-25 15:55:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-25 15:55:03 -0700 |
| commit | 75467f60a3d14f08f86f2b353298d2826382ff23 (patch) | |
| tree | acd8a7d5b5a675042449386efa5b42ec44d8bf81 /fs/squashfs/file_direct.c | |
| download | linux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.tar.gz linux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.zip | |
Merge tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipegrafted
Pull IPE fixes from Fan Wu:
"Two fixes for use-after-free issues found by recent LLM-assisted code
analysis.
- move successful policy load auditing under the new policy
directory's inode lock, preventing a concurrent policy deletion
from freeing the policy while it is still being audited
- protect the dm-verity root hash with RCU, preventing policy
evaluation from racing with root hash replacement during preresume"
* tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe:
ipe: protect the dm-verity root hash with RCU
ipe: fix use-after-free when auditing a newly loaded policy
Diffstat (limited to 'fs/squashfs/file_direct.c')
| -rw-r--r-- | fs/squashfs/file_direct.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c new file mode 100644 index 000000000..2c3e809d6 --- /dev/null +++ b/fs/squashfs/file_direct.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013 + * Phillip Lougher <phillip@squashfs.org.uk> + */ + +#include <linux/fs.h> +#include <linux/vfs.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/pagemap.h> +#include <linux/mutex.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs_fs_i.h" +#include "squashfs.h" +#include "page_actor.h" + +/* Read separately compressed datablock directly into page cache */ +int squashfs_readpage_block(struct folio *folio, u64 block, int bsize, + int expected) +{ + struct page *target_page = &folio->page; + struct inode *inode = folio->mapping->host; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + loff_t file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT; + int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; + loff_t start_index = folio->index & ~mask; + loff_t end_index = start_index | mask; + loff_t index; + int i, pages, bytes, res = -ENOMEM; + struct page **page, *last_page; + struct squashfs_page_actor *actor; + void *pageaddr; + + if (end_index > file_end) + end_index = file_end; + + pages = end_index - start_index + 1; + + page = kmalloc_array(pages, sizeof(void *), GFP_KERNEL); + if (page == NULL) + return res; + + /* Try to grab all the pages covered by the Squashfs block */ + for (i = 0, index = start_index; index <= end_index; index++) { + page[i] = (index == folio->index) ? target_page : + grab_cache_page_nowait(folio->mapping, index); + + if (page[i] == NULL) + continue; + + if (PageUptodate(page[i])) { + unlock_page(page[i]); + put_page(page[i]); + continue; + } + + i++; + } + + pages = i; + + /* + * Create a "page actor" which will kmap and kunmap the + * page cache pages appropriately within the decompressor + */ + actor = squashfs_page_actor_init_special(msblk, page, pages, expected, + start_index << PAGE_SHIFT); + if (actor == NULL) + goto out; + + /* Decompress directly into the page cache buffers */ + res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor); + + last_page = squashfs_page_actor_free(actor); + + if (res < 0) + goto mark_errored; + + if (res != expected || IS_ERR(last_page)) { + res = -EIO; + goto mark_errored; + } + + /* Last page (if present) may have trailing bytes not filled */ + bytes = res % PAGE_SIZE; + if (end_index == file_end && last_page && bytes) { + pageaddr = kmap_local_page(last_page); + memset(pageaddr + bytes, 0, PAGE_SIZE - bytes); + kunmap_local(pageaddr); + } + + /* Mark pages as uptodate, unlock and release */ + for (i = 0; i < pages; i++) { + flush_dcache_page(page[i]); + SetPageUptodate(page[i]); + unlock_page(page[i]); + if (page[i] != target_page) + put_page(page[i]); + } + + kfree(page); + + return 0; + +mark_errored: + /* Decompression failed. Target_page is + * dealt with by the caller + */ + for (i = 0; i < pages; i++) { + if (page[i] == NULL || page[i] == target_page) + continue; + flush_dcache_page(page[i]); + unlock_page(page[i]); + put_page(page[i]); + } + +out: + kfree(page); + return res; +} |
