diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2022-11-29 13:04:52 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-11-29 13:04:52 -0800 |
| commit | f2bb566f5c977ff010baaa9e5e14d9a75b06e5f2 (patch) | |
| tree | 6359cc9169bd06bfb8b757a534c82886df605b71 /fs/file.c | |
| parent | 7a945ce0c19bbdf821d5f7ce1515e7fb8e444465 (diff) | |
| parent | 01f856ae6d0ca5ad0505b79bf2d22d7ca439b2a1 (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
tools/lib/bpf/ringbuf.c
927cbb478adf ("libbpf: Handle size overflow for ringbuf mmap")
b486d19a0ab0 ("libbpf: checkpatch: Fixed code alignments in ringbuf.c")
https://lore.kernel.org/all/20221121122707.44d1446a@canb.auug.org.au/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'fs/file.c')
| -rw-r--r-- | fs/file.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/file.c b/fs/file.c index 5f9c802a5d8d..c942c89ca4cd 100644 --- a/fs/file.c +++ b/fs/file.c @@ -1003,7 +1003,16 @@ static unsigned long __fget_light(unsigned int fd, fmode_t mask) struct files_struct *files = current->files; struct file *file; - if (atomic_read(&files->count) == 1) { + /* + * If another thread is concurrently calling close_fd() followed + * by put_files_struct(), we must not observe the old table + * entry combined with the new refcount - otherwise we could + * return a file that is concurrently being freed. + * + * atomic_read_acquire() pairs with atomic_dec_and_test() in + * put_files_struct(). + */ + if (atomic_read_acquire(&files->count) == 1) { file = files_lookup_fd_raw(files, fd); if (!file || unlikely(file->f_mode & mask)) return 0; |