[PATCH v5 01/17] fs: Fix rw_hint validation
From: Bart Van Assche <bvanassche@acm.org>
Date: 2023-11-30 01:33:32
Also in:
linux-fsdevel, linux-scsi
Subsystem:
file locking (flock() and fcntl()/lockf()), filesystems (vfs and infrastructure), the rest · Maintainers:
Jeff Layton, Chuck Lever, Alexander Viro, Christian Brauner, Linus Torvalds
Reject values that are valid rw_hints after truncation but not before
truncation by passing an untruncated value to rw_hint_valid().
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <redacted>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Rothwell <redacted>
Fixes: 5657cb0797c4 ("fs/fcntl: use copy_to/from_user() for u64 types")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
fs/fcntl.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index c80a6acad742..3ff707bf2743 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c@@ -268,7 +268,7 @@ static int f_getowner_uids(struct file *filp, unsigned long arg) } #endif -static bool rw_hint_valid(enum rw_hint hint) +static bool rw_hint_valid(u64 hint) { switch (hint) { case RWH_WRITE_LIFE_NOT_SET:
@@ -288,19 +288,17 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd, { struct inode *inode = file_inode(file); u64 __user *argp = (u64 __user *)arg; - enum rw_hint hint; - u64 h; + u64 hint; switch (cmd) { case F_GET_RW_HINT: - h = inode->i_write_hint; - if (copy_to_user(argp, &h, sizeof(*argp))) + hint = inode->i_write_hint; + if (copy_to_user(argp, &hint, sizeof(*argp))) return -EFAULT; return 0; case F_SET_RW_HINT: - if (copy_from_user(&h, argp, sizeof(h))) + if (copy_from_user(&hint, argp, sizeof(hint))) return -EFAULT; - hint = (enum rw_hint) h; if (!rw_hint_valid(hint)) return -EINVAL;