nvme: Test a large metadata_len#244
Open
swkim101 wants to merge 1 commit intolinux-blktests:masterfrom
Open
Conversation
Signed-off-by: Sungwoo Kim <[email protected]>
blktests-ci Bot
pushed a commit
to linux-blktests/linux-block
that referenced
this pull request
Apr 20, 2026
pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0. To fix this, add a check to verify that all requested memory is pinned. Reproducer in blktest: linux-blktests/blktests#244 Kernel Oops: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 1061 Comm: nvme-passthroug Not tainted 7.0.0-11783-g90957f9314e8-dirty #16 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:bio_integrity_map_user.cold+0x1b0/0x9d6 Fixes: 492c5d4 ("block: bio-integrity: directly map user buffers") Acked-by: Chao Shi <[email protected]> Acked-by: Weidong Zhu <[email protected]> Acked-by: Dave Tian <[email protected]> Signed-off-by: Sungwoo Kim <[email protected]>
blktests-ci Bot
pushed a commit
to linux-blktests/linux-block
that referenced
this pull request
Apr 21, 2026
pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0. To fix this, add a check to verify that all requested memory is pinned. Reproducer in blktest: linux-blktests/blktests#244 Kernel Oops: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 1061 Comm: nvme-passthroug Not tainted 7.0.0-11783-g90957f9314e8-dirty #16 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:bio_integrity_map_user.cold+0x1b0/0x9d6 Fixes: 492c5d4 ("block: bio-integrity: directly map user buffers") Acked-by: Chao Shi <[email protected]> Acked-by: Weidong Zhu <[email protected]> Acked-by: Dave Tian <[email protected]> Signed-off-by: Sungwoo Kim <[email protected]>
blktests-ci Bot
pushed a commit
to linux-blktests/linux-block
that referenced
this pull request
Apr 22, 2026
pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0. To fix this, add a check to verify that all requested memory is pinned. Reproducer in blktest: linux-blktests/blktests#244 Kernel Oops: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 1061 Comm: nvme-passthroug Not tainted 7.0.0-11783-g90957f9314e8-dirty #16 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:bio_integrity_map_user.cold+0x1b0/0x9d6 Fixes: 492c5d4 ("block: bio-integrity: directly map user buffers") Acked-by: Chao Shi <[email protected]> Acked-by: Weidong Zhu <[email protected]> Acked-by: Dave Tian <[email protected]> Signed-off-by: Sungwoo Kim <[email protected]>
blktests-ci Bot
pushed a commit
to linux-blktests/linux-block
that referenced
this pull request
Apr 23, 2026
pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0. To fix this, add a check to verify that all requested memory is pinned. Reproducer in blktest: linux-blktests/blktests#244 Kernel Oops: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 1061 Comm: nvme-passthroug Not tainted 7.0.0-11783-g90957f9314e8-dirty #16 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:bio_integrity_map_user.cold+0x1b0/0x9d6 Fixes: 492c5d4 ("block: bio-integrity: directly map user buffers") Acked-by: Chao Shi <[email protected]> Acked-by: Weidong Zhu <[email protected]> Acked-by: Dave Tian <[email protected]> Signed-off-by: Sungwoo Kim <[email protected]>
blktests-ci Bot
pushed a commit
to linux-blktests/linux-block
that referenced
this pull request
Apr 24, 2026
pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0. To fix this, add a check to verify that all requested memory is pinned. Reproducer in blktest: linux-blktests/blktests#244 Kernel Oops: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 1061 Comm: nvme-passthroug Not tainted 7.0.0-11783-g90957f9314e8-dirty #16 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:bio_integrity_map_user.cold+0x1b0/0x9d6 Fixes: 492c5d4 ("block: bio-integrity: directly map user buffers") Acked-by: Chao Shi <[email protected]> Acked-by: Weidong Zhu <[email protected]> Acked-by: Dave Tian <[email protected]> Signed-off-by: Sungwoo Kim <[email protected]>
blktests-ci Bot
pushed a commit
to linux-blktests/linux-block
that referenced
this pull request
Apr 24, 2026
pin_user_pages_fast() can partially succeed and return the number of pages that were actually pinned. However, the bio_integrity_map_user() does not handle this partial pinning. This leads to a general protection fault since bvec_from_pages() dereferences an unpinned page address, which is 0. To fix this, add a check to verify that all requested memory is pinned. Reproducer in blktest: linux-blktests/blktests#244 Kernel Oops: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 1061 Comm: nvme-passthroug Not tainted 7.0.0-11783-g90957f9314e8-dirty #16 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 RIP: 0010:bio_integrity_map_user.cold+0x1b0/0x9d6 Fixes: 492c5d4 ("block: bio-integrity: directly map user buffers") Acked-by: Chao Shi <[email protected]> Acked-by: Weidong Zhu <[email protected]> Acked-by: Dave Tian <[email protected]> Signed-off-by: Sungwoo Kim <[email protected]>
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
1 participant
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.
This reproduces a kernel bug[1] that triggers a general protection fault.
The kernel pins a user memory
metadata, which can partially succeed. However, the kernel (bio_integrity_map_user()) does not handle partial pinning and assumes that all requested memory is pinned, leading to a null-ptr-deref.To reproduce this, this testcase makes the kernel partially pin the requested memory by requesting arbitrary large
metadata_len. In my setting,metadata_len=20 * 4096was enough to trigger partial pinning, though the trigger depends on the machine. If a testing machine uses a large page (e.g., 1GB), then it cannot trigger the partial pinning.[1] https://lore.kernel.org/linux-block/[email protected]/