Description
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint Patch series "nilfs2: fix null-ptr-deref bugs on block tracepoints". This series fixes null pointer dereference bugs that occur when using nilfs2 and two block-related tracepoints. This patch (of 2): It has been reported that when using "block:block_touch_buffer" tracepoint, touch_buffer() called from __nilfs_get_folio_block() causes a NULL pointer dereference, or a general protection fault when KASAN is enabled. This happens because since the tracepoint was added in touch_buffer(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure. In the current implementation, the block_device structure is set after the function returns to the caller. Here, touch_buffer() is used to mark the folio/page that owns the buffer head as accessed, but the common search helper for folio/page used by the caller function was optimized to mark the folio/page as accessed when it was reimplemented a long time ago, eliminating the need to call touch_buffer() here in the first place. So this solves the issue by eliminating the touch_buffer() call itself.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
5305cb830834549b9203ad4d009ad5483c5e293f to < 085556bf8c70e2629e02e79268dac3016a08b8bfaffected5305cb830834549b9203ad4d009ad5483c5e293f to < 6438f3f42cda825f6f59b4e45ac3a1da28a6f2c9affected5305cb830834549b9203ad4d009ad5483c5e293f to < b017697a517f8779ada4e8ce1c2c75dbf60a2636affected5305cb830834549b9203ad4d009ad5483c5e293f to < 19c71cdd77973f99a9adc3190130bc3aa7ae5423affected5305cb830834549b9203ad4d009ad5483c5e293f to < 3b2a4fd9bbee77afdd3ed5a05a0c02b6cde8d3b9affected5305cb830834549b9203ad4d009ad5483c5e293f to < 59b49ca67cca7b007a5afd3de0283c8008157665affected5305cb830834549b9203ad4d009ad5483c5e293f to < 77e47f89d32c2d72eb33d0becbce7abe14d061f4affected5305cb830834549b9203ad4d009ad5483c5e293f to < cd45e963e44b0f10d90b9e6c0e8b4f47f3c92471affected
Linux Linux
Default version status: affected
3.9affected0 to < 3.9unaffected4.19.325 to ≤ 4.19.*unaffected5.4.287 to ≤ 5.4.*unaffected5.10.231 to ≤ 5.10.*unaffected5.15.174 to ≤ 5.15.*unaffected6.1.119 to ≤ 6.1.*unaffected6.6.63 to ≤ 6.6.*unaffected6.11.10 to ≤ 6.11.*unaffected6.12 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/085556bf8c70e2629e02e79268dac3016a08b8bf ↗
- https://git.kernel.org/stable/c/6438f3f42cda825f6f59b4e45ac3a1da28a6f2c9 ↗
- https://git.kernel.org/stable/c/b017697a517f8779ada4e8ce1c2c75dbf60a2636 ↗
- https://git.kernel.org/stable/c/19c71cdd77973f99a9adc3190130bc3aa7ae5423 ↗
- https://git.kernel.org/stable/c/3b2a4fd9bbee77afdd3ed5a05a0c02b6cde8d3b9 ↗
- https://git.kernel.org/stable/c/59b49ca67cca7b007a5afd3de0283c8008157665 ↗
- https://git.kernel.org/stable/c/77e47f89d32c2d72eb33d0becbce7abe14d061f4 ↗
- https://git.kernel.org/stable/c/cd45e963e44b0f10d90b9e6c0e8b4f47f3c92471 ↗
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html ↗
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html ↗