July 2024 - Kernel - mailweb.openeuler.org

[PATCH OLK-5.10] scsi: ufs: Fix a deadlock in the error handler
by Pu Lehui 20 Jul '24

20 Jul '24

From: Bart Van Assche <bvanassche(a)acm.org> mainline inclusion from mainline-v5.17-rc1 commit 945c3cca05d78351bba29fa65d93834cb7934c7b category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IADG3U CVE: CVE-2021-47622 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The following deadlock has been observed on a test setup: - All tags allocated - The SCSI error handler calls ufshcd_eh_host_reset_handler() - ufshcd_eh_host_reset_handler() queues work that calls ufshcd_err_handler() - ufshcd_err_handler() locks up as follows: Workqueue: ufs_eh_wq_0 ufshcd_err_handler.cfi_jt Call trace: __switch_to+0x298/0x5d8 __schedule+0x6cc/0xa94 schedule+0x12c/0x298 blk_mq_get_tag+0x210/0x480 __blk_mq_alloc_request+0x1c8/0x284 blk_get_request+0x74/0x134 ufshcd_exec_dev_cmd+0x68/0x640 ufshcd_verify_dev_init+0x68/0x35c ufshcd_probe_hba+0x12c/0x1cb8 ufshcd_host_reset_and_restore+0x88/0x254 ufshcd_reset_and_restore+0xd0/0x354 ufshcd_err_handler+0x408/0xc58 process_one_work+0x24c/0x66c worker_thread+0x3e8/0xa4c kthread+0x150/0x1b4 ret_from_fork+0x10/0x30 Fix this lockup by making ufshcd_exec_dev_cmd() allocate a reserved request. Link: https://lore.kernel.org/r/20211203231950.193369-10-bvanassche@acm.org Tested-by: Bean Huo <beanhuo(a)micron.com> Reviewed-by: Adrian Hunter <adrian.hunter(a)intel.com> Reviewed-by: Bean Huo <beanhuo(a)micron.com> Signed-off-by: Bart Van Assche <bvanassche(a)acm.org> Signed-off-by: Martin K. Petersen <martin.petersen(a)oracle.com> Conflicts: drivers/scsi/ufs/ufshcd.c [The Conflicts were due to not backport some unnecessary patch] Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- drivers/scsi/ufs/ufshcd.c | 52 +++++++++++---------------------------- drivers/scsi/ufs/ufshcd.h | 2 ++ 2 files changed, 16 insertions(+), 38 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 129c45c6bba5..3aa8a600e9a5 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -125,8 +125,9 @@ EXPORT_SYMBOL_GPL(ufshcd_dump_regs); enum { UFSHCD_MAX_CHANNEL = 0, UFSHCD_MAX_ID = 1, - UFSHCD_CMD_PER_LUN = 32, - UFSHCD_CAN_QUEUE = 32, + UFSHCD_NUM_RESERVED = 1, + UFSHCD_CMD_PER_LUN = 32 - UFSHCD_NUM_RESERVED, + UFSHCD_CAN_QUEUE = 32 - UFSHCD_NUM_RESERVED, }; /* UFSHCD states */ @@ -2046,6 +2047,7 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba) hba->nutrs = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS) + 1; hba->nutmrs = ((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1; + hba->reserved_slot = hba->nutrs - 1; /* Read crypto capabilities */ err = ufshcd_hba_init_crypto_capabilities(hba); @@ -2774,31 +2776,16 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba, static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, enum dev_cmd_type cmd_type, int timeout) { - struct request_queue *q = hba->cmd_queue; - struct request *req; + const u32 tag = hba->reserved_slot; struct ufshcd_lrb *lrbp; int err; - int tag; struct completion wait; unsigned long flags; - down_read(&hba->clk_scaling_lock); + /* Protects use of hba->reserved_slot. */ + lockdep_assert_held(&hba->dev_cmd.lock); - /* - * Get free slot, sleep if slots are unavailable. - * Even though we use wait_event() which sleeps indefinitely, - * the maximum wait time is bounded by SCSI request timeout. - */ - req = blk_get_request(q, REQ_OP_DRV_OUT, 0); - if (IS_ERR(req)) { - err = PTR_ERR(req); - goto out_unlock; - } - tag = req->tag; - WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag)); - /* Set the timeout such that the SCSI error handler is not activated. */ - req->timeout = msecs_to_jiffies(2 * timeout); - blk_mq_start_request(req); + down_read(&hba->clk_scaling_lock); init_completion(&wait); lrbp = &hba->lrb[tag]; @@ -2822,8 +2809,6 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, err ? "query_complete_err" : "query_complete"); out_put_tag: - blk_put_request(req); -out_unlock: up_read(&hba->clk_scaling_lock); return err; } @@ -6380,24 +6365,17 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, enum dev_cmd_type cmd_type, enum query_opcode desc_op) { - struct request_queue *q = hba->cmd_queue; - struct request *req; + const u32 tag = hba->reserved_slot; struct ufshcd_lrb *lrbp; int err = 0; - int tag; struct completion wait; unsigned long flags; u8 upiu_flags; - down_read(&hba->clk_scaling_lock); + /* Protects use of hba->reserved_slot. */ + lockdep_assert_held(&hba->dev_cmd.lock); - req = blk_get_request(q, REQ_OP_DRV_OUT, 0); - if (IS_ERR(req)) { - err = PTR_ERR(req); - goto out_unlock; - } - tag = req->tag; - WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag)); + down_read(&hba->clk_scaling_lock); init_completion(&wait); lrbp = &hba->lrb[tag]; @@ -6474,8 +6452,6 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, } } - blk_put_request(req); -out_unlock: up_read(&hba->clk_scaling_lock); return err; } @@ -9146,8 +9122,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) /* Configure LRB */ ufshcd_host_memory_configure(hba); - host->can_queue = hba->nutrs; - host->cmd_per_lun = hba->nutrs; + host->can_queue = hba->nutrs - UFSHCD_NUM_RESERVED; + host->cmd_per_lun = hba->nutrs - UFSHCD_NUM_RESERVED; host->max_id = UFSHCD_MAX_ID; host->max_lun = UFS_MAX_LUNS; host->max_channel = UFSHCD_MAX_CHANNEL; diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 35dd5197ccb9..160a6ef58942 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -634,6 +634,7 @@ struct ufs_hba_variant_params { * @capabilities: UFS Controller Capabilities * @nutrs: Transfer Request Queue depth supported by controller * @nutmrs: Task Management Queue depth supported by controller + * @reserved_slot: Used to submit device commands. Protected by @dev_cmd.lock. * @ufs_version: UFS Version to which controller complies * @vops: pointer to variant specific operations * @priv: pointer to variant specific private data @@ -719,6 +720,7 @@ struct ufs_hba { u32 capabilities; int nutrs; int nutmrs; + u32 reserved_slot; u32 ufs_version; const struct ufs_hba_variant_ops *vops; struct ufs_hba_variant_params *vps; -- 2.34.1

2 1

[PATCH openEuler-22.03-LTS-SP1 0/3] CVE-2024-35931
by Liu Chuang 20 Jul '24

20 Jul '24

Fixing CVE-2024-35931 Asad Kamal (1): drm/amdgpu : Add hive ras recovery check Liu Chuang (1): drm/amdgpu: Fix kabi breakage in struct amdgpu_hive_info Stanley.Yang (1): drm/amdgpu: Skip do PCI error slot reset during RAS recovery drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 16 ++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 9 +++++++-- drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h | 2 ++ 3 files changed, 25 insertions(+), 2 deletions(-) -- 2.34.1

2 4

[PATCH OLK-5.10] bpf: Fix overrunning reservations in ringbuf
by Pu Lehui 20 Jul '24

20 Jul '24

From: Daniel Borkmann <daniel(a)iogearbox.net> mainline inclusion from mainline-v6.10-rc6 commit cfa1a2329a691ffd991fcf7248a57d752e712881 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IADR59 CVE: CVE-2024-41009 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The BPF ring buffer internally is implemented as a power-of-2 sized circular buffer, with two logical and ever-increasing counters: consumer_pos is the consumer counter to show which logical position the consumer consumed the data, and producer_pos which is the producer counter denoting the amount of data reserved by all producers. Each time a record is reserved, the producer that "owns" the record will successfully advance producer counter. In user space each time a record is read, the consumer of the data advanced the consumer counter once it finished processing. Both counters are stored in separate pages so that from user space, the producer counter is read-only and the consumer counter is read-write. One aspect that simplifies and thus speeds up the implementation of both producers and consumers is how the data area is mapped twice contiguously back-to-back in the virtual memory, allowing to not take any special measures for samples that have to wrap around at the end of the circular buffer data area, because the next page after the last data page would be first data page again, and thus the sample will still appear completely contiguous in virtual memory. Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for book-keeping the length and offset, and is inaccessible to the BPF program. Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ` for the BPF program to use. Bing-Jhong and Muhammad reported that it is however possible to make a second allocated memory chunk overlapping with the first chunk and as a result, the BPF program is now able to edit first chunk's header. For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in [0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets allocate a chunk B with size 0x3000. This will succeed because consumer_pos was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask` check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data pages. This means that chunk B at [0x4000,0x4008] is chunk A's header. bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong page and could cause a crash. Fix it by calculating the oldest pending_pos and check whether the range from the oldest outstanding record to the newest would span beyond the ring buffer size. If that is the case, then reject the request. We've tested with the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh) before/after the fix and while it seems a bit slower on some benchmarks, it is still not significantly enough to matter. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Reported-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Reported-by: Muhammad Ramdhan <ramdhan(a)starlabs.sg> Co-developed-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Co-developed-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Link: https://lore.kernel.org/bpf/20240621140828.18238-1-daniel@iogearbox.net Conflicts: kernel/bpf/ringbuf.c [The Conflicts were due to not merge commit 583c1f420173f] Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- kernel/bpf/ringbuf.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c index d6fbe17432ae..d21d4ba2eb39 100644 --- a/kernel/bpf/ringbuf.c +++ b/kernel/bpf/ringbuf.c @@ -44,6 +44,7 @@ struct bpf_ringbuf { */ unsigned long consumer_pos __aligned(PAGE_SIZE); unsigned long producer_pos __aligned(PAGE_SIZE); + unsigned long pending_pos; char data[] __aligned(PAGE_SIZE); }; @@ -145,6 +146,7 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node) rb->mask = data_sz - 1; rb->consumer_pos = 0; rb->producer_pos = 0; + rb->pending_pos = 0; return rb; } @@ -323,9 +325,9 @@ bpf_ringbuf_restore_from_rec(struct bpf_ringbuf_hdr *hdr) static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size) { - unsigned long cons_pos, prod_pos, new_prod_pos, flags; - u32 len, pg_off; + unsigned long cons_pos, prod_pos, new_prod_pos, pend_pos, flags; struct bpf_ringbuf_hdr *hdr; + u32 len, pg_off, tmp_size, hdr_len; if (unlikely(size > RINGBUF_MAX_RECORD_SZ)) return NULL; @@ -343,13 +345,29 @@ static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size) spin_lock_irqsave(&rb->spinlock, flags); } + pend_pos = rb->pending_pos; prod_pos = rb->producer_pos; new_prod_pos = prod_pos + len; - /* check for out of ringbuf space by ensuring producer position - * doesn't advance more than (ringbuf_size - 1) ahead + while (pend_pos < prod_pos) { + hdr = (void *)rb->data + (pend_pos & rb->mask); + hdr_len = READ_ONCE(hdr->len); + if (hdr_len & BPF_RINGBUF_BUSY_BIT) + break; + tmp_size = hdr_len & ~BPF_RINGBUF_DISCARD_BIT; + tmp_size = round_up(tmp_size + BPF_RINGBUF_HDR_SZ, 8); + pend_pos += tmp_size; + } + rb->pending_pos = pend_pos; + + /* check for out of ringbuf space: + * - by ensuring producer position doesn't advance more than + * (ringbuf_size - 1) ahead + * - by ensuring oldest not yet committed record until newest + * record does not span more than (ringbuf_size - 1) */ - if (new_prod_pos - cons_pos > rb->mask) { + if (new_prod_pos - cons_pos > rb->mask || + new_prod_pos - pend_pos > rb->mask) { spin_unlock_irqrestore(&rb->spinlock, flags); return NULL; } -- 2.34.1

2 1

[PATCH openEuler-22.03-LTS-SP1] bpf: Fix overrunning reservations in ringbuf
by Pu Lehui 20 Jul '24

20 Jul '24

From: Daniel Borkmann <daniel(a)iogearbox.net> mainline inclusion from mainline-v6.10-rc6 commit cfa1a2329a691ffd991fcf7248a57d752e712881 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IADR59 CVE: CVE-2024-41009 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The BPF ring buffer internally is implemented as a power-of-2 sized circular buffer, with two logical and ever-increasing counters: consumer_pos is the consumer counter to show which logical position the consumer consumed the data, and producer_pos which is the producer counter denoting the amount of data reserved by all producers. Each time a record is reserved, the producer that "owns" the record will successfully advance producer counter. In user space each time a record is read, the consumer of the data advanced the consumer counter once it finished processing. Both counters are stored in separate pages so that from user space, the producer counter is read-only and the consumer counter is read-write. One aspect that simplifies and thus speeds up the implementation of both producers and consumers is how the data area is mapped twice contiguously back-to-back in the virtual memory, allowing to not take any special measures for samples that have to wrap around at the end of the circular buffer data area, because the next page after the last data page would be first data page again, and thus the sample will still appear completely contiguous in virtual memory. Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for book-keeping the length and offset, and is inaccessible to the BPF program. Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ` for the BPF program to use. Bing-Jhong and Muhammad reported that it is however possible to make a second allocated memory chunk overlapping with the first chunk and as a result, the BPF program is now able to edit first chunk's header. For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in [0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets allocate a chunk B with size 0x3000. This will succeed because consumer_pos was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask` check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data pages. This means that chunk B at [0x4000,0x4008] is chunk A's header. bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong page and could cause a crash. Fix it by calculating the oldest pending_pos and check whether the range from the oldest outstanding record to the newest would span beyond the ring buffer size. If that is the case, then reject the request. We've tested with the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh) before/after the fix and while it seems a bit slower on some benchmarks, it is still not significantly enough to matter. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Reported-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Reported-by: Muhammad Ramdhan <ramdhan(a)starlabs.sg> Co-developed-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Co-developed-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Link: https://lore.kernel.org/bpf/20240621140828.18238-1-daniel@iogearbox.net Conflicts: kernel/bpf/ringbuf.c [The Conflicts were due to not merge commit 583c1f420173f] Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- kernel/bpf/ringbuf.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c index d6fbe17432ae..d21d4ba2eb39 100644 --- a/kernel/bpf/ringbuf.c +++ b/kernel/bpf/ringbuf.c @@ -44,6 +44,7 @@ struct bpf_ringbuf { */ unsigned long consumer_pos __aligned(PAGE_SIZE); unsigned long producer_pos __aligned(PAGE_SIZE); + unsigned long pending_pos; char data[] __aligned(PAGE_SIZE); }; @@ -145,6 +146,7 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node) rb->mask = data_sz - 1; rb->consumer_pos = 0; rb->producer_pos = 0; + rb->pending_pos = 0; return rb; } @@ -323,9 +325,9 @@ bpf_ringbuf_restore_from_rec(struct bpf_ringbuf_hdr *hdr) static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size) { - unsigned long cons_pos, prod_pos, new_prod_pos, flags; - u32 len, pg_off; + unsigned long cons_pos, prod_pos, new_prod_pos, pend_pos, flags; struct bpf_ringbuf_hdr *hdr; + u32 len, pg_off, tmp_size, hdr_len; if (unlikely(size > RINGBUF_MAX_RECORD_SZ)) return NULL; @@ -343,13 +345,29 @@ static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size) spin_lock_irqsave(&rb->spinlock, flags); } + pend_pos = rb->pending_pos; prod_pos = rb->producer_pos; new_prod_pos = prod_pos + len; - /* check for out of ringbuf space by ensuring producer position - * doesn't advance more than (ringbuf_size - 1) ahead + while (pend_pos < prod_pos) { + hdr = (void *)rb->data + (pend_pos & rb->mask); + hdr_len = READ_ONCE(hdr->len); + if (hdr_len & BPF_RINGBUF_BUSY_BIT) + break; + tmp_size = hdr_len & ~BPF_RINGBUF_DISCARD_BIT; + tmp_size = round_up(tmp_size + BPF_RINGBUF_HDR_SZ, 8); + pend_pos += tmp_size; + } + rb->pending_pos = pend_pos; + + /* check for out of ringbuf space: + * - by ensuring producer position doesn't advance more than + * (ringbuf_size - 1) ahead + * - by ensuring oldest not yet committed record until newest + * record does not span more than (ringbuf_size - 1) */ - if (new_prod_pos - cons_pos > rb->mask) { + if (new_prod_pos - cons_pos > rb->mask || + new_prod_pos - pend_pos > rb->mask) { spin_unlock_irqrestore(&rb->spinlock, flags); return NULL; } -- 2.34.1

2 1

[PATCH OLK-6.6] bpf: Fix overrunning reservations in ringbuf
by Pu Lehui 20 Jul '24

20 Jul '24

From: Daniel Borkmann <daniel(a)iogearbox.net> stable inclusion from stable-v6.6.37 commit 511804ab701c0503b72eac08217eabfd366ba069 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IADR59 CVE: CVE-2024-41009 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit cfa1a2329a691ffd991fcf7248a57d752e712881 ] The BPF ring buffer internally is implemented as a power-of-2 sized circular buffer, with two logical and ever-increasing counters: consumer_pos is the consumer counter to show which logical position the consumer consumed the data, and producer_pos which is the producer counter denoting the amount of data reserved by all producers. Each time a record is reserved, the producer that "owns" the record will successfully advance producer counter. In user space each time a record is read, the consumer of the data advanced the consumer counter once it finished processing. Both counters are stored in separate pages so that from user space, the producer counter is read-only and the consumer counter is read-write. One aspect that simplifies and thus speeds up the implementation of both producers and consumers is how the data area is mapped twice contiguously back-to-back in the virtual memory, allowing to not take any special measures for samples that have to wrap around at the end of the circular buffer data area, because the next page after the last data page would be first data page again, and thus the sample will still appear completely contiguous in virtual memory. Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for book-keeping the length and offset, and is inaccessible to the BPF program. Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ` for the BPF program to use. Bing-Jhong and Muhammad reported that it is however possible to make a second allocated memory chunk overlapping with the first chunk and as a result, the BPF program is now able to edit first chunk's header. For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in [0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets allocate a chunk B with size 0x3000. This will succeed because consumer_pos was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask` check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data pages. This means that chunk B at [0x4000,0x4008] is chunk A's header. bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong page and could cause a crash. Fix it by calculating the oldest pending_pos and check whether the range from the oldest outstanding record to the newest would span beyond the ring buffer size. If that is the case, then reject the request. We've tested with the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh) before/after the fix and while it seems a bit slower on some benchmarks, it is still not significantly enough to matter. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Reported-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Reported-by: Muhammad Ramdhan <ramdhan(a)starlabs.sg> Co-developed-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Co-developed-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Bing-Jhong Billy Jheng <billy(a)starlabs.sg> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Link: https://lore.kernel.org/bpf/20240621140828.18238-1-daniel@iogearbox.net Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- kernel/bpf/ringbuf.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c index f045fde632e5..238d9b206bbd 100644 --- a/kernel/bpf/ringbuf.c +++ b/kernel/bpf/ringbuf.c @@ -51,7 +51,8 @@ struct bpf_ringbuf { * This prevents a user-space application from modifying the * position and ruining in-kernel tracking. The permissions of the * pages depend on who is producing samples: user-space or the - * kernel. + * kernel. Note that the pending counter is placed in the same + * page as the producer, so that it shares the same cache line. * * Kernel-producer * --------------- @@ -70,6 +71,7 @@ struct bpf_ringbuf { */ unsigned long consumer_pos __aligned(PAGE_SIZE); unsigned long producer_pos __aligned(PAGE_SIZE); + unsigned long pending_pos; char data[] __aligned(PAGE_SIZE); }; @@ -179,6 +181,7 @@ static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node) rb->mask = data_sz - 1; rb->consumer_pos = 0; rb->producer_pos = 0; + rb->pending_pos = 0; return rb; } @@ -404,9 +407,9 @@ bpf_ringbuf_restore_from_rec(struct bpf_ringbuf_hdr *hdr) static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size) { - unsigned long cons_pos, prod_pos, new_prod_pos, flags; - u32 len, pg_off; + unsigned long cons_pos, prod_pos, new_prod_pos, pend_pos, flags; struct bpf_ringbuf_hdr *hdr; + u32 len, pg_off, tmp_size, hdr_len; if (unlikely(size > RINGBUF_MAX_RECORD_SZ)) return NULL; @@ -424,13 +427,29 @@ static void *__bpf_ringbuf_reserve(struct bpf_ringbuf *rb, u64 size) spin_lock_irqsave(&rb->spinlock, flags); } + pend_pos = rb->pending_pos; prod_pos = rb->producer_pos; new_prod_pos = prod_pos + len; - /* check for out of ringbuf space by ensuring producer position - * doesn't advance more than (ringbuf_size - 1) ahead + while (pend_pos < prod_pos) { + hdr = (void *)rb->data + (pend_pos & rb->mask); + hdr_len = READ_ONCE(hdr->len); + if (hdr_len & BPF_RINGBUF_BUSY_BIT) + break; + tmp_size = hdr_len & ~BPF_RINGBUF_DISCARD_BIT; + tmp_size = round_up(tmp_size + BPF_RINGBUF_HDR_SZ, 8); + pend_pos += tmp_size; + } + rb->pending_pos = pend_pos; + + /* check for out of ringbuf space: + * - by ensuring producer position doesn't advance more than + * (ringbuf_size - 1) ahead + * - by ensuring oldest not yet committed record until newest + * record does not span more than (ringbuf_size - 1) */ - if (new_prod_pos - cons_pos > rb->mask) { + if (new_prod_pos - cons_pos > rb->mask || + new_prod_pos - pend_pos > rb->mask) { spin_unlock_irqrestore(&rb->spinlock, flags); return NULL; } -- 2.34.1

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[PATCH OLK-6.6 0/2] CVE-2024-35931
by Liu Chuang 20 Jul '24

20 Jul '24

Fixing CVE-2024-35931 Asad Kamal (1): drm/amdgpu : Add hive ras recovery check Stanley.Yang (1): drm/amdgpu: Skip do PCI error slot reset during RAS recovery drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 14 ++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 9 +++++++-- drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h | 1 + .../gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c | 10 +++++++++- 4 files changed, 31 insertions(+), 3 deletions(-) -- 2.34.1

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[PATCH OLK-6.6] cxl/region: Fix memregion leaks in devm_cxl_add_region()
by Pu Lehui 20 Jul '24

20 Jul '24

From: Li Zhijian <lizhijian(a)fujitsu.com> stable inclusion from stable-v6.6.35 commit d8316838aa0686da63a8be4194b7a17b0103ae4a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAD6H2 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit 49ba7b515c4c0719b866d16f068e62d16a8a3dd1 ] Move the mode verification to __create_region() before allocating the memregion to avoid the memregion leaks. Fixes: 6e099264185d ("cxl/region: Add volatile region creation support") Signed-off-by: Li Zhijian <lizhijian(a)fujitsu.com> Reviewed-by: Dan Williams <dan.j.williams(a)intel.com> Link: https://lore.kernel.org/r/20240507053421.456439-1-lizhijian@fujitsu.com Signed-off-by: Dave Jiang <dave.jiang(a)intel.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- drivers/cxl/core/region.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index e2a82ee4ff0c..6f06255012f0 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2186,15 +2186,6 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd, struct device *dev; int rc; - switch (mode) { - case CXL_DECODER_RAM: - case CXL_DECODER_PMEM: - break; - default: - dev_err(&cxlrd->cxlsd.cxld.dev, "unsupported mode %d\n", mode); - return ERR_PTR(-EINVAL); - } - cxlr = cxl_region_alloc(cxlrd, id); if (IS_ERR(cxlr)) return cxlr; @@ -2245,6 +2236,15 @@ static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd, { int rc; + switch (mode) { + case CXL_DECODER_RAM: + case CXL_DECODER_PMEM: + break; + default: + dev_err(&cxlrd->cxlsd.cxld.dev, "unsupported mode %d\n", mode); + return ERR_PTR(-EINVAL); + } + rc = memregion_alloc(GFP_KERNEL); if (rc < 0) return ERR_PTR(rc); -- 2.34.1

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[PATCH OLK-5.10 0/3] CVE-2024-35931
by Liu Chuang 20 Jul '24

20 Jul '24

Fixing CVE-2024-35931 Asad Kamal (1): drm/amdgpu : Add hive ras recovery check Liu Chuang (1): drm/amdgpu: Fix kabi breakage in struct amdgpu_hive_info Stanley.Yang (1): drm/amdgpu: Skip do PCI error slot reset during RAS recovery drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 16 ++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 9 +++++++-- drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h | 2 ++ 3 files changed, 25 insertions(+), 2 deletions(-) -- 2.34.1

2 4

[PATCH OLK-6.6 0/2] CVE-2024-35931
by Liu Chuang 20 Jul '24

20 Jul '24

Fixing CVE-2024-35931 Asad Kamal (1): drm/amdgpu : Add hive ras recovery check Stanley.Yang (1): drm/amdgpu: Skip do PCI error slot reset during RAS recovery drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 14 ++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 9 +++++++-- drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h | 1 + .../gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c | 10 +++++++++- 4 files changed, 31 insertions(+), 3 deletions(-) -- 2.34.1

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[PATCH openEuler-22.03-LTS-SP1 0/3] CVE-2024-35931
by Liu Chuang 20 Jul '24

20 Jul '24

Fixing CVE-2024-35931 Asad Kamal (1): drm/amdgpu : Add hive ras recovery check Liu Chuang (1): drm/amdgpu: Fix kabi breakage in struct amdgpu_hive_info Stanley.Yang (1): drm/amdgpu: Skip do PCI error slot reset during RAS recovery drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 16 ++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 9 +++++++-- drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h | 2 ++ 3 files changed, 25 insertions(+), 2 deletions(-) -- 2.34.1

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