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| author | Miklos Szeredi <mszeredi@redhat.com> | 2020-02-06 16:39:28 +0100 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2020-02-06 16:39:28 +0100 |
| commit | 2f1398291bf35fe027914ae7a9610d8e601fbfde (patch) | |
| tree | bf2d245ba2d6ea3937423cc5080228474b759a76 /fs/fuse | |
| parent | fix up iter on short count in fuse_direct_io() (diff) | |
| download | linux-2f1398291bf35fe027914ae7a9610d8e601fbfde.tar.xz linux-2f1398291bf35fe027914ae7a9610d8e601fbfde.zip | |
fuse: don't overflow LLONG_MAX with end offset
Handle the special case of fuse_readpages() wanting to read the last page
of a hugest file possible and overflowing the end offset in the process.
This is basically to unbreak xfstests:generic/525 and prevent filesystems
from doing bad things with an overflowing offset.
Reported-by: Xiao Yang <ice_yangxiao@163.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse')
| -rw-r--r-- | fs/fuse/file.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 695369f46f92..3dd37a998ea9 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -803,6 +803,10 @@ static int fuse_do_readpage(struct file *file, struct page *page) attr_ver = fuse_get_attr_version(fc); + /* Don't overflow end offset */ + if (pos + (desc.length - 1) == LLONG_MAX) + desc.length--; + fuse_read_args_fill(&ia, file, pos, desc.length, FUSE_READ); res = fuse_simple_request(fc, &ia.ap.args); if (res < 0) @@ -888,6 +892,14 @@ static void fuse_send_readpages(struct fuse_io_args *ia, struct file *file) ap->args.out_pages = true; ap->args.page_zeroing = true; ap->args.page_replace = true; + + /* Don't overflow end offset */ + if (pos + (count - 1) == LLONG_MAX) { + count--; + ap->descs[ap->num_pages - 1].length--; + } + WARN_ON((loff_t) (pos + count) < 0); + fuse_read_args_fill(ia, file, pos, count, FUSE_READ); ia->read.attr_ver = fuse_get_attr_version(fc); if (fc->async_read) { |