CVE-2026-43445: e1000/e1000e: Fix leak in DMA error cleanup

CVE-2026-43445: e1000/e1000e: Fix leak in DMA error cleanup

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

e1000/e1000e: Fix leak in DMA error cleanup

If an error is encountered while mapping TX buffers, the driver should
unmap any buffers already mapped for that skb.

Because count is incremented after a successful mapping, it will always
match the correct number of unmappings needed when dma_error is reached.
Decrementing count before the while loop in dma_error causes an
off-by-one error. If any mapping was successful before an unsuccessful
mapping, exactly one DMA mapping would leak.

In these commits, a faulty while condition caused an infinite loop in
dma_error:
Commit 03b1320dfcee ("e1000e: remove use of skb_dma_map from e1000e
driver")
Commit 602c0554d7b0 ("e1000: remove use of skb_dma_map from e1000 driver")

Commit c1fa347f20f1 ("e1000/e1000e/igb/igbvf/ixgb/ixgbe: Fix tests of
unsigned in *_tx_map()") fixed the infinite loop, but introduced the
off-by-one error.

This issue may still exist in the igbvf driver, but I did not address it
in this patch.

The Linux kernel CVE team has assigned CVE-2026-43445 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 5.10.253 with commit 7eaeb778bfaa3b2a804f89321c234d59c74569db
	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 5.15.203 with commit 0606c24a745bafd1be5d66c48361638cd9cad74b
	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 6.1.167 with commit 519051c711dfd239ef6e4b28878efee400a035f9
	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 6.6.130 with commit 0a1fc25deabab4efce64610e3c449485c4fa8f5f
	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 6.12.78 with commit fa5ba9867a55e640df0dc79bf0199770fb043f03
	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 6.18.19 with commit 30e87ade8d678c25a8546cf38c0b498fa5cb27d3
	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 6.19.9 with commit 10b5e65959e955a1c8894e0a5413944b5a70204a
	Issue introduced in 2.6.33 with commit c1fa347f20f17f14a4a1575727fa24340e8a9117 and fixed in 7.0 with commit e94eaef11142b01f77bf8ba4d0b59720b7858109

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-43445
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/intel/e1000/e1000_main.c
	drivers/net/ethernet/intel/e1000e/netdev.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/7eaeb778bfaa3b2a804f89321c234d59c74569db
	https://git.kernel.org/stable/c/0606c24a745bafd1be5d66c48361638cd9cad74b
	https://git.kernel.org/stable/c/519051c711dfd239ef6e4b28878efee400a035f9
	https://git.kernel.org/stable/c/0a1fc25deabab4efce64610e3c449485c4fa8f5f
	https://git.kernel.org/stable/c/fa5ba9867a55e640df0dc79bf0199770fb043f03
	https://git.kernel.org/stable/c/30e87ade8d678c25a8546cf38c0b498fa5cb27d3
	https://git.kernel.org/stable/c/10b5e65959e955a1c8894e0a5413944b5a70204a
	https://git.kernel.org/stable/c/e94eaef11142b01f77bf8ba4d0b59720b7858109