WSL2-Linux-Kernel/include
Mikulas Patocka d4252071b9 add barriers to buffer_uptodate and set_buffer_uptodate
Let's have a look at this piece of code in __bread_slow:

	get_bh(bh);
	bh->b_end_io = end_buffer_read_sync;
	submit_bh(REQ_OP_READ, 0, bh);
	wait_on_buffer(bh);
	if (buffer_uptodate(bh))
		return bh;

Neither wait_on_buffer nor buffer_uptodate contain any memory barrier.
Consequently, if someone calls sb_bread and then reads the buffer data,
the read of buffer data may be executed before wait_on_buffer(bh) on
architectures with weak memory ordering and it may return invalid data.

Fix this bug by adding a memory barrier to set_buffer_uptodate and an
acquire barrier to buffer_uptodate (in a similar way as
folio_test_uptodate and folio_mark_uptodate).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-08-09 15:03:02 -07:00
..
acpi
asm-generic Bitmap patches for v6.0-rc1 2022-08-07 17:52:35 -07:00
clocksource
crypto for-5.20/block-2022-08-04 2022-08-04 20:00:14 -07:00
drm
dt-bindings sound updates for 6.0-rc1 2022-08-06 10:19:51 -07:00
keys
kunit
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linux add barriers to buffer_uptodate and set_buffer_uptodate 2022-08-09 15:03:02 -07:00
math-emu
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trace NFSD 6.0 Release Notes 2022-08-09 14:56:49 -07:00
uapi TTY / Serial driver changes for 6.0-rc1 2022-08-08 11:31:40 -07:00
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