From: Jens Axboe <[email protected]>
To: [email protected], [email protected]
Cc: [email protected], [email protected], [email protected],
Jens Axboe <[email protected]>
Subject: [PATCH 04/12] futex: Validate futex value against futex size
Date: Fri, 28 Jul 2023 10:42:27 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
From: Peter Zijlstra <[email protected]>
Ensure the futex value fits in the given futex size. Since this adds a
constraint to an existing syscall, it might possibly change behaviour.
Currently the value would be truncated to a u32 and any high bits
would get silently lost.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
---
kernel/futex/futex.h | 8 ++++++++
kernel/futex/syscalls.c | 3 +++
2 files changed, 11 insertions(+)
diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h
index c0e04599904a..d0a43d751e30 100644
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -86,6 +86,14 @@ static inline unsigned int futex_size(unsigned int flags)
return 1 << size; /* {0,1,2,3} -> {1,2,4,8} */
}
+static inline bool futex_validate_input(unsigned int flags, u64 val)
+{
+ int bits = 8 * futex_size(flags);
+ if (bits < 64 && (val >> bits))
+ return false;
+ return true;
+}
+
#ifdef CONFIG_FAIL_FUTEX
extern bool should_fail_futex(bool fshared);
#else
diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c
index 36824b64219a..d2b2bcf2a665 100644
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -209,6 +209,9 @@ static int futex_parse_waitv(struct futex_vector *futexv,
if (!futex_flags_valid(flags))
return -EINVAL;
+ if (!futex_validate_input(flags, aux.val))
+ return -EINVAL;
+
futexv[i].w.flags = flags;
futexv[i].w.val = aux.val;
futexv[i].w.uaddr = aux.uaddr;
--
2.40.1
next prev parent reply other threads:[~2023-07-28 16:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-28 16:42 [PATCHSET v4] Add io_uring futex/futexv support Jens Axboe
2023-07-28 16:42 ` [PATCH 01/12] futex: Clarify FUTEX2 flags Jens Axboe
2023-07-28 16:42 ` [PATCH 02/12] futex: Extend the " Jens Axboe
2023-07-28 16:42 ` [PATCH 03/12] futex: Flag conversion Jens Axboe
2023-08-09 18:04 ` Gabriel Krisman Bertazi
2023-07-28 16:42 ` Jens Axboe [this message]
2023-07-28 16:42 ` [PATCH 05/12] futex: move FUTEX2_MASK to futex.h Jens Axboe
2023-07-28 16:42 ` [PATCH 06/12] futex: factor out the futex wake handling Jens Axboe
2023-07-28 16:42 ` [PATCH 07/12] futex: abstract out a __futex_wake_mark() helper Jens Axboe
2023-07-28 16:42 ` [PATCH 08/12] io_uring: add support for futex wake and wait Jens Axboe
2023-07-28 16:42 ` [PATCH 09/12] futex: add wake_data to struct futex_q Jens Axboe
2023-07-28 16:42 ` [PATCH 10/12] futex: make futex_parse_waitv() available as a helper Jens Axboe
2023-07-28 16:42 ` [PATCH 11/12] futex: make the vectored futex operations available Jens Axboe
2023-07-28 16:42 ` [PATCH 12/12] io_uring: add support for vectored futex waits Jens Axboe
2023-07-31 16:06 ` [PATCHSET v4] Add io_uring futex/futexv support Thomas Gleixner
2023-08-06 16:44 ` Jens Axboe
2023-08-07 1:23 ` Thomas Gleixner
2023-08-07 18:23 ` Jens Axboe
2023-08-15 0:12 ` Thomas Gleixner
2023-08-15 0:18 ` Jens Axboe
2023-08-15 0:47 ` Thomas Gleixner
2023-08-15 1:51 ` Jens Axboe
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