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| author | Phillip Lougher <phillip@squashfs.org.uk> | 2018-08-02 18:45:15 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-02 19:34:02 +0300 |
| commit | a3f94cb99a854fa381fe7fadd97c4f61633717a5 (patch) | |
| tree | 9de67b4b1fa9b93ded20dc65bd4b7fd059ef6813 /fs/squashfs/file_direct.c | |
| parent | 71755ee5350b63fb1f283de8561cdb61b47f4d1d (diff) | |
| download | linux-a3f94cb99a854fa381fe7fadd97c4f61633717a5.tar.xz | |
Squashfs: Compute expected length from inode size rather than block length
Previously in squashfs_readpage() when copying data into the page
cache, it used the length of the datablock read from the filesystem
(after decompression). However, if the filesystem has been corrupted
this data block may be short, which will leave pages unfilled.
The fix for this is to compute the expected number of bytes to copy
from the inode size, and use this to detect if the block is short.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: Анатолий Тросиненко <anatoly.trosinenko@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/squashfs/file_direct.c')
| -rw-r--r-- | fs/squashfs/file_direct.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c index 096990254a2e..80db1b86a27c 100644 --- a/fs/squashfs/file_direct.c +++ b/fs/squashfs/file_direct.c @@ -21,10 +21,11 @@ #include "page_actor.h" static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, - int pages, struct page **page); + int pages, struct page **page, int bytes); /* Read separately compressed datablock directly into page cache */ -int squashfs_readpage_block(struct page *target_page, u64 block, int bsize) +int squashfs_readpage_block(struct page *target_page, u64 block, int bsize, + int expected) { struct inode *inode = target_page->mapping->host; @@ -83,7 +84,7 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize) * using an intermediate buffer. */ res = squashfs_read_cache(target_page, block, bsize, pages, - page); + page, expected); if (res < 0) goto mark_errored; @@ -95,6 +96,11 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize) if (res < 0) goto mark_errored; + if (res != expected) { + res = -EIO; + goto mark_errored; + } + /* Last page may have trailing bytes not filled */ bytes = res % PAGE_SIZE; if (bytes) { @@ -138,12 +144,12 @@ out: static int squashfs_read_cache(struct page *target_page, u64 block, int bsize, - int pages, struct page **page) + int pages, struct page **page, int bytes) { struct inode *i = target_page->mapping->host; struct squashfs_cache_entry *buffer = squashfs_get_datablock(i->i_sb, block, bsize); - int bytes = buffer->length, res = buffer->error, n, offset = 0; + int res = buffer->error, n, offset = 0; if (res) { ERROR("Unable to read page, block %llx, size %x\n", block, |