linux: Improve panic message for out-of-range fds in FD_* functions - #5528
Open
danielcanencia wants to merge 1 commit into
Open
danielcanencia wants to merge 1 commit into
danielcanencia wants to merge 1 commit into
Conversation
Passing a file descriptor that is negative or >= FD_SETSIZE to FD_SET, FD_CLR or FD_ISSET is undefined behavior per POSIX, and the previous "index out of bounds" panic gave no hint of the required range. Panic with a message that states the valid 0..FD_SETSIZE range instead. Source: https://github.com/bminor/glibc/blob/d2097651cc57834dbfcaa102ddfacae0d86cfb66/misc/sys/select.h Part of rust-lang#1401 Signed-off-by: Daniel Canencia Garcia <danielcanenciagarcia@gmail.com>
tgross35
requested changes
Sep 15, 2026
Comment on lines
-1850
to
+1852
| (*set).fds_bits[fd / size] &= !(1 << (fd % size)); | ||
| return; | ||
| *(*set).fds_bits.get_mut(fd / size).unwrap_or_else(|| { | ||
| core::panic!("fd {fd} out of range: valid fds are 0..FD_SETSIZE (0..{FD_SETSIZE})") | ||
| }) &= !(1 << (fd % size)); |
Member
There was a problem hiding this comment.
This is tough to read, use let Some(...) = ... else { ... } instead
| (*set).fds_bits[fd / size] &= !(1 << (fd % size)); | ||
| return; | ||
| *(*set).fds_bits.get_mut(fd / size).unwrap_or_else(|| { | ||
| core::panic!("fd {fd} out of range: valid fds are 0..FD_SETSIZE (0..{FD_SETSIZE})") |
Member
There was a problem hiding this comment.
Add panic! to the prelude (update the macro_rules! prelude)
| @@ -1847,21 +1847,26 @@ f! { | |||
| pub unsafe fn FD_CLR(fd: c_int, set: *mut fd_set) -> () { | |||
Member
There was a problem hiding this comment.
Could you please update these functions everywhere they exist? They exist in a lot of modules, not just Linux.
Collaborator
|
Reminder, once the PR becomes ready for a review, use |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Part of #1401
Fixes the out-of-bounds FD_SET/FD_CLR/FD_ISSET panic for Linux
(linux_like). The issue also calls for the same clear panic message in
other platforms; those remain a follow-up (cygwin, haiku, solaris, etc).
Note:
is nothing to range-check.