FAILED: Patch "io_uring/filetable: clamp alloc_hint to the configured alloc range" failed to apply to 6.1-stable tree

PATCH Sasha Levin 2 participants 7 messages Mar 1 – Mar 2

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Stable branch io_uring

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Sasha Levin

author maintainer

2026-03-01 01:47 UTC #0 lore raw

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From a6bded921ed35f21b3f6bd8e629bf488499ca442 Mon Sep 17 00:00:00 2001
From: Jens Axboe <[email protected]>
Date: Wed, 11 Feb 2026 15:12:03 -0700
Subject: [PATCH] io_uring/filetable: clamp alloc_hint to the configured alloc
range

Explicit fixed file install/remove operations on slots outside the configured alloc range can corrupt alloc_hint via io_file_bitmap_set() and io_file_bitmap_clear(), which unconditionally update alloc_hint to the bit position. This causes subsequent auto-allocations to fall outside the configured range.

For example, if the alloc range is [10, 20) and a file is removed at slot 2, alloc_hint gets set to 2. The next auto-alloc then starts searching from slot 2, potentially returning a slot below the range.

Fix this by clamping alloc_hint to [file_alloc_start, file_alloc_end) at the top of io_file_bitmap_get() before starting the search.

Cc [email protected]

Fixes 6e73dffbb93c ("io_uring: let to set a range for file slot allocation")

Signed-off-by Jens Axboe <[email protected]>

---
 io_uring/filetable.c | 4 ++++
 1 file changed, 4 insertions(+)

io_uring/filetable.c +4 -0

index 794ef95df293c..cb1838c9fc377 100644
@@ -22,6 +22,10 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx)
 	if (!table->bitmap)
 		return -ENFILE;
 
+	if (table->alloc_hint < ctx->file_alloc_start ||
+	    table->alloc_hint >= ctx->file_alloc_end)
+		table->alloc_hint = ctx->file_alloc_start;
+
 	do {
 		ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint);
 		if (ret != nr)

Signature · 1 line

2.51.0

Jens Axboe

maintainer

2026-03-01 13:15 UTC #1 lore raw

Quoted 4 lines · Sasha Levin

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

And this one also picks cleanly into 6.1-stable. Not sure what is going on at your end?

Signature · 1 line

Jens Axboe

Jens Axboe

maintainer

2026-03-02 20:38 UTC #2 lore raw

Quoted 8 lines · Jens Axboe

Quoted 4 lines · Sasha Levin
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
And this one also picks cleanly into 6.1-stable. Not sure what is going on at your end?

Are these and the other "FAILED" false positives getting applied or not? I didn't hear anything back on any of them.

Signature · 1 line

Jens Axboe

Sasha Levin

author maintainer

2026-03-02 20:42 UTC #3 lore raw

Quoted 7 lines · Jens Axboe

Quoted 6 lines · Jens Axboe
Quoted 4 lines · Sasha Levin
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Quoted 5 lines

Quoted 2 lines
And this one also picks cleanly into 6.1-stable. Not sure what is going on at your end?
Are these and the other "FAILED" false positives getting applied or not? I didn't hear anything back on any of them.

Appologies for all of this. There's an explanation of what happened here:
https://lore.kernel.org/all/aaWWE5uQqz_eG69i@laps/

These should be part of the -rc2 I did earlier today.

Signature · 2 lines

Thanks,
Sasha

Jens Axboe

maintainer

2026-03-02 20:45 UTC #4 lore raw

Quoted 11 lines · Sasha Levin

Quoted 10 lines · Jens Axboe
Quoted 8 lines · Jens Axboe
Quoted 4 lines · Sasha Levin
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
And this one also picks cleanly into 6.1-stable. Not sure what is going on at your end?

Quoted 7 lines

Quoted 2 lines
Are these and the other "FAILED" false positives getting applied or not? I didn't hear anything back on any of them.
Appologies for all of this. There's an explanation of what happened here:
https://lore.kernel.org/all/aaWWE5uQqz_eG69i@laps/
These should be part of the -rc2 I did earlier today.

Gotcha, yeah it's not easy to know when you don't hear back, either as a reply or as a new "added to stable" email. For those of us that do take stable seriously, I 100% need to know if something is landing or not.

Signature · 1 line

Jens Axboe

Sasha Levin

author maintainer

2026-03-02 20:58 UTC #5 lore raw

Quoted 18 lines · Jens Axboe

Quoted 17 lines · Sasha Levin
Quoted 7 lines · Jens Axboe
Quoted 6 lines · Jens Axboe
Quoted 4 lines · Sasha Levin
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Quoted 5 lines
Quoted 2 lines
And this one also picks cleanly into 6.1-stable. Not sure what is going on at your end?
Are these and the other "FAILED" false positives getting applied or not? I didn't hear anything back on any of them.
Appologies for all of this. There's an explanation of what happened here:
https://lore.kernel.org/all/aaWWE5uQqz_eG69i@laps/

Quoted 6 lines

Quoted 1 line
These should be part of the -rc2 I did earlier today.
Gotcha, yeah it's not easy to know when you don't hear back, either as a reply or as a new "added to stable" email. For those of us that do take stable seriously, I 100% need to know if something is landing or not.

You're right (and thanks for all the backports!). I had a plan to review all of these again after the release, but I should have sent something out first.

Signature · 2 lines

Thanks,
Sasha

Jens Axboe

maintainer

2026-03-02 21:08 UTC #6 lore raw

Quoted 21 lines · Sasha Levin

Quoted 20 lines · Jens Axboe
Quoted 18 lines · Sasha Levin
Quoted 7 lines · Jens Axboe
Quoted 6 lines · Jens Axboe
Quoted 4 lines · Sasha Levin
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Quoted 5 lines
Quoted 2 lines
And this one also picks cleanly into 6.1-stable. Not sure what is going on at your end?
Are these and the other "FAILED" false positives getting applied or not? I didn't hear anything back on any of them.
Appologies for all of this. There's an explanation of what happened here:
https://lore.kernel.org/all/aaWWE5uQqz_eG69i@laps/
These should be part of the -rc2 I did earlier today.

Quoted 8 lines

Quoted 4 lines
Gotcha, yeah it's not easy to know when you don't hear back, either as a reply or as a new "added to stable" email. For those of us that do take stable seriously, I 100% need to know if something is landing or not.
You're right (and thanks for all the backports!). I had a plan to review all of these again after the release, but I should have sent something out first.

Sounds good, it was more of a note for the future, should something like this happen again.

Signature · 1 line

Jens Axboe