From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- io_uring/advise.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 io_uring/advise.c (limited to 'io_uring/advise.c') diff --git a/io_uring/advise.c b/io_uring/advise.c new file mode 100644 index 000000000..0073f74e3 --- /dev/null +++ b/io_uring/advise.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "io_uring.h" +#include "advise.h" + +struct io_fadvise { + struct file *file; + u64 offset; + u64 len; + u32 advice; +}; + +struct io_madvise { + struct file *file; + u64 addr; + u64 len; + u32 advice; +}; + +int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) + struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise); + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + + ma->addr = READ_ONCE(sqe->addr); + ma->len = READ_ONCE(sqe->off); + if (!ma->len) + ma->len = READ_ONCE(sqe->len); + ma->advice = READ_ONCE(sqe->fadvise_advice); + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +int io_madvise(struct io_kiocb *req, unsigned int issue_flags) +{ +#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) + struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK); + + ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +#else + return -EOPNOTSUPP; +#endif +} + +static bool io_fadvise_force_async(struct io_fadvise *fa) +{ + switch (fa->advice) { + case POSIX_FADV_NORMAL: + case POSIX_FADV_RANDOM: + case POSIX_FADV_SEQUENTIAL: + return false; + default: + return true; + } +} + +int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise); + + if (sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + + fa->offset = READ_ONCE(sqe->off); + fa->len = READ_ONCE(sqe->addr); + if (!fa->len) + fa->len = READ_ONCE(sqe->len); + fa->advice = READ_ONCE(sqe->fadvise_advice); + if (io_fadvise_force_async(fa)) + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +int io_fadvise(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise); + int ret; + + WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK && io_fadvise_force_async(fa)); + + ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} -- cgit v1.3.1