- Linux-stable-mirror - lists.linaro.org

[PATCH v4] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

by Zhen Ni

When fsl_edma_alloc_chan_resources() fails after clk_prepare_enable(), the error paths only free IRQs and destroy the TCD pool, but forget to call clk_disable_unprepare(). This causes the channel clock to remain enabled, leaking power and resources. Fix it by disabling the channel clock in the error unwind path. Fixes: d8d4355861d8 ("dmaengine: fsl-edma: add i.MX8ULP edma support") Cc: stable(a)vger.kernel.org Suggested-by: Frank Li <Frank.Li(a)nxp.com> Signed-off-by: Zhen Ni <zhen.ni(a)easystack.cn> --- Changes in v2: - Remove FSL_EDMA_DRV_HAS_CHCLK check Changes in v3: - Remove cleanup Changes in v4: - Re-send as a new thread --- drivers/dma/fsl-edma-common.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c index 4976d7dde080..11655dcc4d6c 100644 --- a/drivers/dma/fsl-edma-common.c +++ b/drivers/dma/fsl-edma-common.c @@ -852,6 +852,7 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan) free_irq(fsl_chan->txirq, fsl_chan); err_txirq: dma_pool_destroy(fsl_chan->tcd_pool); + clk_disable_unprepare(fsl_chan->clk); return ret; } -- 2.20.1

8 hours, 34 minutes

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[PATCH v3 2/4] tpm2-sessions: Fix tpm2_read_public range checks

by Jarkko Sakkinen

'tpm2_read_public' has some rudimentary range checks but the function does not ensure that the response buffer has enough bytes for the full TPMT_HA payload. Re-implement the function with necessary checks and validation. Cc: stable(a)vger.kernel.org # v6.10+ Fixes: d0a25bb961e6 ("tpm: Add HMAC session name/handle append") Signed-off-by: Jarkko Sakkinen <jarkko(a)kernel.org> v2: - Made the fix localized instead of spread all over the place. --- drivers/char/tpm/tpm2-cmd.c | 3 ++ drivers/char/tpm/tpm2-sessions.c | 77 +++++++++++++++++--------------- 2 files changed, 44 insertions(+), 36 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index be4a9c7f2e1a..34e3599f094f 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -11,8 +11,11 @@ * used by the kernel internally. */ +#include "linux/dev_printk.h" +#include "linux/tpm.h" #include "tpm.h" #include <crypto/hash_info.h> +#include <linux/unaligned.h> static bool disable_pcr_integrity; module_param(disable_pcr_integrity, bool, 0444); diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index a265e9752a5e..e9f439be3916 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -163,54 +163,59 @@ static int name_size(const u8 *name) } } -static int tpm2_parse_read_public(char *name, struct tpm_buf *buf) +static int tpm2_read_public(struct tpm_chip *chip, u32 handle, void *name) { - struct tpm_header *head = (struct tpm_header *)buf->data; + u32 mso = tpm2_handle_mso(handle); off_t offset = TPM_HEADER_SIZE; - u32 tot_len = be32_to_cpu(head->length); - int ret; - u32 val; - - /* we're starting after the header so adjust the length */ - tot_len -= TPM_HEADER_SIZE; - - /* skip public */ - val = tpm_buf_read_u16(buf, &offset); - if (val > tot_len) - return -EINVAL; - offset += val; - /* name */ - - val = tpm_buf_read_u16(buf, &offset); - ret = name_size(&buf->data[offset]); - if (ret < 0) - return ret; + struct tpm_buf buf; + int rc, rc2; - if (val != ret) + if (mso != TPM2_MSO_PERSISTENT && mso != TPM2_MSO_VOLATILE && + mso != TPM2_MSO_NVRAM) return -EINVAL; - memcpy(name, &buf->data[offset], val); - /* forget the rest */ - return 0; -} - -static int tpm2_read_public(struct tpm_chip *chip, u32 handle, char *name) -{ - struct tpm_buf buf; - int rc; - rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_READ_PUBLIC); if (rc) return rc; tpm_buf_append_u32(&buf, handle); - rc = tpm_transmit_cmd(chip, &buf, 0, "read public"); - if (rc == TPM2_RC_SUCCESS) - rc = tpm2_parse_read_public(name, &buf); - tpm_buf_destroy(&buf); + rc = tpm_transmit_cmd(chip, &buf, 0, "TPM2_ReadPublic"); + if (rc) { + tpm_buf_destroy(&buf); + return tpm_ret_to_err(rc); + } - return rc; + /* Skip TPMT_PUBLIC: */ + offset += tpm_buf_read_u16(&buf, &offset); + + /* + * Ensure space for the length field of TPM2B_NAME and hashAlg field of + * TPMT_HA (the extra four bytes). + */ + if (offset + 4 > tpm_buf_length(&buf)) { + tpm_buf_destroy(&buf); + return -EIO; + } + + rc = tpm_buf_read_u16(&buf, &offset); + rc2 = name_size(&buf.data[offset]); + + if (rc2 < 0) + return rc2; + + if (rc != rc2) { + tpm_buf_destroy(&buf); + return -EIO; + } + + if (offset + rc > tpm_buf_length(&buf)) { + tpm_buf_destroy(&buf); + return -EIO; + } + + memcpy(name, &buf.data[offset], rc); + return 0; } #endif /* CONFIG_TCG_TPM2_HMAC */ -- 2.52.0

8 hours, 36 minutes

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[PATCH v3 1/4] tpm2-sessions: fix out of range indexing in name_size

by Jarkko Sakkinen

'name_size' does not have any range checks, and it just directly indexes with TPM_ALG_ID, which could lead into memory corruption at worst. Address the issue by only processing known values and returning -EINVAL for unrecognized values. Make also 'tpm_buf_append_name' and 'tpm_buf_fill_hmac_session' fallible so that errors are detected before causing any spurious TPM traffic. End also the authorization session on failure in both of the functions, as the session state would be then by definition corrupted. Cc: stable(a)vger.kernel.org # v6.10+ Fixes: 1085b8276bb4 ("tpm: Add the rest of the session HMAC API") Signed-off-by: Jarkko Sakkinen <jarkko(a)kernel.org> v3: - Fix pr_warn() format string in name_size(). - Fix !CONFIG_TPM2_HMAC compilation. v2: - Wrote a better short summary. - Addressed remarks in https://lore.kernel.org/linux-integrity/aS8TIeviaippVAha@earth.li/ - Use -EIO consistently in tpm2_fill_hmac_session. These are not input value errors. They could only spun from malformed (kernel) state. - name_size did not have a proper default-case. Reorganize the fallback into that. --- drivers/char/tpm/tpm2-cmd.c | 23 +++- drivers/char/tpm/tpm2-sessions.c | 133 +++++++++++++++------- include/linux/tpm.h | 13 ++- security/keys/trusted-keys/trusted_tpm2.c | 29 ++++- 4 files changed, 143 insertions(+), 55 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index dd502322f499..be4a9c7f2e1a 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -199,7 +199,11 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, } if (!disable_pcr_integrity) { - tpm_buf_append_name(chip, &buf, pcr_idx, NULL); + rc = tpm_buf_append_name(chip, &buf, pcr_idx, NULL); + if (rc) { + tpm_buf_destroy(&buf); + return rc; + } tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0); } else { tpm_buf_append_handle(chip, &buf, pcr_idx); @@ -214,8 +218,14 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, chip->allocated_banks[i].digest_size); } - if (!disable_pcr_integrity) - tpm_buf_fill_hmac_session(chip, &buf); + if (!disable_pcr_integrity) { + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) { + tpm_buf_destroy(&buf); + return rc; + } + } + rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value"); if (!disable_pcr_integrity) rc = tpm_buf_check_hmac_response(chip, &buf, rc); @@ -273,7 +283,12 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) | TPM2_SA_CONTINUE_SESSION, NULL, 0); tpm_buf_append_u16(&buf, num_bytes); - tpm_buf_fill_hmac_session(chip, &buf); + err = tpm_buf_fill_hmac_session(chip, &buf); + if (err) { + tpm_buf_destroy(&buf); + return err; + } + err = tpm_transmit_cmd(chip, &buf, offsetof(struct tpm2_get_random_out, buffer), diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 6d03c224e6b2..a265e9752a5e 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -144,16 +144,23 @@ struct tpm2_auth { /* * Name Size based on TPM algorithm (assumes no hash bigger than 255) */ -static u8 name_size(const u8 *name) +static int name_size(const u8 *name) { - static u8 size_map[] = { - [TPM_ALG_SHA1] = SHA1_DIGEST_SIZE, - [TPM_ALG_SHA256] = SHA256_DIGEST_SIZE, - [TPM_ALG_SHA384] = SHA384_DIGEST_SIZE, - [TPM_ALG_SHA512] = SHA512_DIGEST_SIZE, - }; - u16 alg = get_unaligned_be16(name); - return size_map[alg] + 2; + u16 hash_alg = get_unaligned_be16(name); + + switch (hash_alg) { + case TPM_ALG_SHA1: + return SHA1_DIGEST_SIZE + 2; + case TPM_ALG_SHA256: + return SHA256_DIGEST_SIZE + 2; + case TPM_ALG_SHA384: + return SHA384_DIGEST_SIZE + 2; + case TPM_ALG_SHA512: + return SHA512_DIGEST_SIZE + 2; + default: + pr_warn("tpm: unsupported name algorithm: 0x%04x\n", hash_alg); + return -EINVAL; + } } static int tpm2_parse_read_public(char *name, struct tpm_buf *buf) @@ -161,6 +168,7 @@ static int tpm2_parse_read_public(char *name, struct tpm_buf *buf) struct tpm_header *head = (struct tpm_header *)buf->data; off_t offset = TPM_HEADER_SIZE; u32 tot_len = be32_to_cpu(head->length); + int ret; u32 val; /* we're starting after the header so adjust the length */ @@ -172,9 +180,15 @@ static int tpm2_parse_read_public(char *name, struct tpm_buf *buf) return -EINVAL; offset += val; /* name */ + val = tpm_buf_read_u16(buf, &offset); - if (val != name_size(&buf->data[offset])) + ret = name_size(&buf->data[offset]); + if (ret < 0) + return ret; + + if (val != ret) return -EINVAL; + memcpy(name, &buf->data[offset], val); /* forget the rest */ return 0; @@ -221,46 +235,72 @@ static int tpm2_read_public(struct tpm_chip *chip, u32 handle, char *name) * As with most tpm_buf operations, success is assumed because failure * will be caused by an incorrect programming model and indicated by a * kernel message. + * + * Ends the authorization session on failure. */ -void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, - u32 handle, u8 *name) +int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, + u32 handle, u8 *name) { #ifdef CONFIG_TCG_TPM2_HMAC enum tpm2_mso_type mso = tpm2_handle_mso(handle); struct tpm2_auth *auth; int slot; + int ret; #endif if (!tpm2_chip_auth(chip)) { tpm_buf_append_handle(chip, buf, handle); - return; + return 0; } #ifdef CONFIG_TCG_TPM2_HMAC slot = (tpm_buf_length(buf) - TPM_HEADER_SIZE) / 4; if (slot >= AUTH_MAX_NAMES) { - dev_err(&chip->dev, "TPM: too many handles\n"); - return; + dev_err(&chip->dev, "too many handles\n"); + ret = -EIO; + goto err; } auth = chip->auth; - WARN(auth->session != tpm_buf_length(buf), - "name added in wrong place\n"); + if (auth->session != tpm_buf_length(buf)) { + dev_err(&chip->dev, "session state malformed"); + ret = -EIO; + goto err; + } tpm_buf_append_u32(buf, handle); auth->session += 4; if (mso == TPM2_MSO_PERSISTENT || mso == TPM2_MSO_VOLATILE || mso == TPM2_MSO_NVRAM) { - if (!name) - tpm2_read_public(chip, handle, auth->name[slot]); + if (!name) { + ret = tpm2_read_public(chip, handle, auth->name[slot]); + if (ret) + goto err; + } } else { - if (name) - dev_err(&chip->dev, "TPM: Handle does not require name but one is specified\n"); + if (name) { + dev_err(&chip->dev, "handle 0x%08x does not use a name\n", + handle); + ret = -EIO; + goto err; + } } auth->name_h[slot] = handle; - if (name) - memcpy(auth->name[slot], name, name_size(name)); + if (name) { + ret = name_size(name); + if (ret < 0) + goto err; + + memcpy(auth->name[slot], name, ret); + } +#endif + return 0; + +#ifdef CONFIG_TCG_TPM2_HMAC +err: + tpm2_end_auth_session(chip); + return tpm_ret_to_err(ret); #endif } EXPORT_SYMBOL_GPL(tpm_buf_append_name); @@ -533,11 +573,9 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip, * encryption key and encrypts the first parameter of the command * buffer with it. * - * As with most tpm_buf operations, success is assumed because failure - * will be caused by an incorrect programming model and indicated by a - * kernel message. + * Ends the authorization session on failure. */ -void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) +int tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) { u32 cc, handles, val; struct tpm2_auth *auth = chip->auth; @@ -549,9 +587,12 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) u8 cphash[SHA256_DIGEST_SIZE]; struct sha256_ctx sctx; struct hmac_sha256_ctx hctx; + int ret; - if (!auth) - return; + if (!auth) { + ret = -EIO; + goto err; + } /* save the command code in BE format */ auth->ordinal = head->ordinal; @@ -560,9 +601,11 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) i = tpm2_find_cc(chip, cc); if (i < 0) { - dev_err(&chip->dev, "Command 0x%x not found in TPM\n", cc); - return; + dev_err(&chip->dev, "command 0x%08x not found\n", cc); + ret = -EIO; + goto err; } + attrs = chip->cc_attrs_tbl[i]; handles = (attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0); @@ -576,9 +619,9 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) u32 handle = tpm_buf_read_u32(buf, &offset_s); if (auth->name_h[i] != handle) { - dev_err(&chip->dev, "TPM: handle %d wrong for name\n", - i); - return; + dev_err(&chip->dev, "invalid handle 0x%08x\n", handle); + ret = -EIO; + goto err; } } /* point offset_s to the start of the sessions */ @@ -609,12 +652,14 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) offset_s += len; } if (offset_s != offset_p) { - dev_err(&chip->dev, "TPM session length is incorrect\n"); - return; + dev_err(&chip->dev, "session length is incorrect\n"); + ret = -EIO; + goto err; } if (!hmac) { - dev_err(&chip->dev, "TPM could not find HMAC session\n"); - return; + dev_err(&chip->dev, "could not find HMAC session\n"); + ret = -EIO; + goto err; } /* encrypt before HMAC */ @@ -646,8 +691,11 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) if (mso == TPM2_MSO_PERSISTENT || mso == TPM2_MSO_VOLATILE || mso == TPM2_MSO_NVRAM) { - sha256_update(&sctx, auth->name[i], - name_size(auth->name[i])); + ret = name_size(auth->name[i]); + if (ret < 0) + goto err; + + sha256_update(&sctx, auth->name[i], ret); } else { __be32 h = cpu_to_be32(auth->name_h[i]); @@ -668,6 +716,11 @@ void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) hmac_sha256_update(&hctx, auth->tpm_nonce, sizeof(auth->tpm_nonce)); hmac_sha256_update(&hctx, &auth->attrs, 1); hmac_sha256_final(&hctx, hmac); + return 0; + +err: + tpm2_end_auth_session(chip); + return ret; } EXPORT_SYMBOL(tpm_buf_fill_hmac_session); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 3d8f7d1ce2b8..aa816b144ab3 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -529,8 +529,8 @@ static inline struct tpm2_auth *tpm2_chip_auth(struct tpm_chip *chip) #endif } -void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, - u32 handle, u8 *name); +int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, + u32 handle, u8 *name); void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf, u8 attributes, u8 *passphrase, int passphraselen); @@ -563,7 +563,7 @@ static inline void tpm_buf_append_hmac_session_opt(struct tpm_chip *chip, #ifdef CONFIG_TCG_TPM2_HMAC int tpm2_start_auth_session(struct tpm_chip *chip); -void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf); +int tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf); int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, int rc); void tpm2_end_auth_session(struct tpm_chip *chip); @@ -577,10 +577,13 @@ static inline int tpm2_start_auth_session(struct tpm_chip *chip) static inline void tpm2_end_auth_session(struct tpm_chip *chip) { } -static inline void tpm_buf_fill_hmac_session(struct tpm_chip *chip, - struct tpm_buf *buf) + +static inline int tpm_buf_fill_hmac_session(struct tpm_chip *chip, + struct tpm_buf *buf) { + return 0; } + static inline int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, int rc) diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 8bc6efa8accb..5b205279584b 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -268,7 +268,10 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out_put; } - tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + if (rc) + goto out; + tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT, options->keyauth, TPM_DIGEST_SIZE); @@ -316,7 +319,10 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out; } - tpm_buf_fill_hmac_session(chip, &buf); + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) + goto out; + rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data"); rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (rc) @@ -427,7 +433,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip, return rc; } - tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + if (rc) + goto out; + tpm_buf_append_hmac_session(chip, &buf, 0, options->keyauth, TPM_DIGEST_SIZE); @@ -439,7 +448,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip, goto out; } - tpm_buf_fill_hmac_session(chip, &buf); + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) + goto out; + rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob"); rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (!rc) @@ -484,7 +496,9 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, return rc; } - tpm_buf_append_name(chip, &buf, blob_handle, NULL); + rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + if (rc) + goto out; if (!options->policyhandle) { tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT, @@ -509,7 +523,10 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, NULL, 0); } - tpm_buf_fill_hmac_session(chip, &buf); + rc = tpm_buf_fill_hmac_session(chip, &buf); + if (rc) + goto out; + rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); rc = tpm_buf_check_hmac_response(chip, &buf, rc); -- 2.52.0

8 hours, 36 minutes

1
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[PATCH 1/2] x86/amd_node: fix integer divide by zero during init

by Steven Noonan

On a Xen dom0 boot, this feature does not behave, and we end up calculating: num_roots = 1 num_nodes = 2 roots_per_node = 0 This causes a divide-by-zero in the modulus inside the loop. This change adds a couple of guards for invalid states where we might get a divide-by-zero. Signed-off-by: Steven Noonan <steven(a)uplinklabs.net> Signed-off-by: Ariadne Conill <ariadne(a)ariadne.space> CC: Yazen Ghannam <yazen.ghannam(a)amd.com> CC: x86(a)vger.kernel.org CC: stable(a)vger.kernel.org --- arch/x86/kernel/amd_node.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kernel/amd_node.c b/arch/x86/kernel/amd_node.c index 3d0a4768d603c..cdc6ba224d4ad 100644 --- a/arch/x86/kernel/amd_node.c +++ b/arch/x86/kernel/amd_node.c @@ -282,6 +282,17 @@ static int __init amd_smn_init(void) return -ENODEV; num_nodes = amd_num_nodes(); + + if (!num_nodes) + return -ENODEV; + + /* Possibly a virtualized environment (e.g. Xen) where we wi ll get + * roots_per_node=0 if the number of roots is fewer than number of + * nodes + */ + if (num_roots < num_nodes) + return -ENODEV; + amd_roots = kcalloc(num_nodes, sizeof(*amd_roots), GFP_KERNEL); if (!amd_roots) return -ENOMEM; -- 2.51.2

9 hours, 30 minutes

3
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[PATCH 0/2] PCI: dwc: Fix missing iATU setup when ECAM is enabled

by Krishna Chaitanya Chundru

When ECAM is enabled, the driver skipped calling dw_pcie_iatu_setup() before configuring ECAM iATU entries. This left IO and MEM outbound windows unprogrammed, resulting in broken IO transactions. Additionally, dw_pcie_config_ecam_iatu() was only called during host initialization, so ECAM-related iATU entries were not restored after suspend/resume, leading to failures in configuration space access. To resolve these issues, the ECAM iATU configuration is moved into dw_pcie_setup_rc(). At the same time, dw_pcie_iatu_setup() is invoked when ECAM is enabled. Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru(a)oss.qualcomm.com> --- Krishna Chaitanya Chundru (2): PCI: dwc: Correct iATU index increment for MSG TLP region PCI: dwc: Fix missing iATU setup when ECAM is enabled drivers/pci/controller/dwc/pcie-designware-host.c | 37 ++++++++++++++--------- drivers/pci/controller/dwc/pcie-designware.c | 3 ++ drivers/pci/controller/dwc/pcie-designware.h | 2 +- 3 files changed, 26 insertions(+), 16 deletions(-) --- base-commit: 3f9f0252130e7dd60d41be0802bf58f6471c691d change-id: 20251203-ecam_io_fix-6e060fecd3b8 Best regards, -- Krishna Chaitanya Chundru <krishna.chundru(a)oss.qualcomm.com>

10 hours, 8 minutes

2
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[PATCH AUTOSEL 6.18-6.1] perf/x86/amd: Check event before enable to avoid GPF

by Sasha Levin

From: George Kennedy <george.kennedy(a)oracle.com> [ Upstream commit 866cf36bfee4fba6a492d2dcc5133f857e3446b0 ] On AMD machines cpuc->events[idx] can become NULL in a subtle race condition with NMI->throttle->x86_pmu_stop(). Check event for NULL in amd_pmu_enable_all() before enable to avoid a GPF. This appears to be an AMD only issue. Syzkaller reported a GPF in amd_pmu_enable_all. INFO: NMI handler (perf_event_nmi_handler) took too long to run: 13.143 msecs Oops: general protection fault, probably for non-canonical address 0xdffffc0000000034: 0000 PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000001a0-0x00000000000001a7] CPU: 0 UID: 0 PID: 328415 Comm: repro_36674776 Not tainted 6.12.0-rc1-syzk RIP: 0010:x86_pmu_enable_event (arch/x86/events/perf_event.h:1195 arch/x86/events/core.c:1430) RSP: 0018:ffff888118009d60 EFLAGS: 00010012 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000034 RSI: 0000000000000000 RDI: 00000000000001a0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 R13: ffff88811802a440 R14: ffff88811802a240 R15: ffff8881132d8601 FS: 00007f097dfaa700(0000) GS:ffff888118000000(0000) GS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c0 CR3: 0000000103d56000 CR4: 00000000000006f0 Call Trace: <IRQ> amd_pmu_enable_all (arch/x86/events/amd/core.c:760 (discriminator 2)) x86_pmu_enable (arch/x86/events/core.c:1360) event_sched_out (kernel/events/core.c:1191 kernel/events/core.c:1186 kernel/events/core.c:2346) __perf_remove_from_context (kernel/events/core.c:2435) event_function (kernel/events/core.c:259) remote_function (kernel/events/core.c:92 (discriminator 1) kernel/events/core.c:72 (discriminator 1)) __flush_smp_call_function_queue (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/csd.h:64 kernel/smp.c:135 kernel/smp.c:540) __sysvec_call_function_single (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./arch/x86/include/asm/trace/irq_vectors.h:99 arch/x86/kernel/smp.c:272) sysvec_call_function_single (arch/x86/kernel/smp.c:266 (discriminator 47) arch/x86/kernel/smp.c:266 (discriminator 47)) </IRQ> Reported-by: syzkaller <syzkaller(a)googlegroups.com> Signed-off-by: George Kennedy <george.kennedy(a)oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: Now I have a complete understanding of this commit. Let me provide a comprehensive analysis. --- ## COMPREHENSIVE ANALYSIS: perf/x86/amd: Check event before enable to avoid GPF ### 1. COMMIT MESSAGE ANALYSIS **Subject:** "perf/x86/amd: Check event before enable to avoid GPF" **Key indicators in the commit message:** - **"GPF" (General Protection Fault)**: A serious kernel crash/oops - critical bug - **"race condition"**: Real bug, not theoretical - found and triggered - **"Syzkaller reported"**: Kernel fuzzer found a reproducible issue - **"Reported-by: syzkaller"**: Confirms the bug is triggerable - **"Signed-off-by: Peter Zijlstra (Intel)"**: Reviewed and signed by top perf maintainer **Missing tags:** - No "Fixes:" tag pointing to the original buggy commit - No "Cc: stable(a)vger.kernel.org" tag ### 2. CODE CHANGE ANALYSIS **The Bug Mechanism:** The race condition occurs between two code paths: **Path 1 - Normal enable path:** ```c // In amd_pmu_enable_all() for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) { if (!test_bit(idx, cpuc->active_mask)) // Check 1 continue; amd_pmu_enable_event(cpuc->events[idx]); // Dereference } ``` **Path 2 - NMI throttle path:** ```c // In x86_pmu_stop() called from NMI->throttle if (test_bit(hwc->idx, cpuc->active_mask)) { __clear_bit(hwc->idx, cpuc->active_mask); // Clear bit cpuc->events[hwc->idx] = NULL; // Set to NULL ... } ``` **The Race:** 1. CPU executes `amd_pmu_enable_all()` during an IPI (`remote_function`/`event_function`) 2. Code passes `test_bit(idx, cpuc->active_mask)` check ✓ 3. **NMI fires** before `cpuc->events[idx]` is read 4. NMI handler throttles an event → calls `x86_pmu_stop()` 5. `x86_pmu_stop()` clears `active_mask` bit AND sets `cpuc->events[idx] = NULL` 6. NMI returns 7. Original code tries to dereference `cpuc->events[idx]` → **NULL pointer dereference → GPF** **The Fix:** ```c // After the fix if (!test_bit(idx, cpuc->active_mask)) continue; /* FIXME: cpuc->events[idx] can become NULL in a subtle race - condition with NMI->throttle->x86_pmu_stop(). */ if (cpuc->events[idx]) amd_pmu_enable_event(cpuc->events[idx]); ``` The fix adds a simple NULL check before dereferencing the pointer. The "FIXME" comment acknowledges this is a workaround for a deeper architectural issue in the event lifecycle, but is correct and safe. ### 3. CLASSIFICATION | Criterion | Assessment | |-----------|------------| | Type | **Bug fix** - NULL pointer dereference causing kernel crash | | Severity | **High** - Causes kernel oops/GPF | | Category | Not a new feature, device ID, quirk, or DT update | | Security | Not explicitly a CVE, but denial-of-service via crash | ### 4. SCOPE AND RISK ASSESSMENT **Change Statistics:** - **Lines changed:** 6 added, 1 removed (+5 net) - **Files affected:** 1 (`arch/x86/events/amd/core.c`) - **Functions modified:** 1 (`amd_pmu_enable_all()`) **Risk Assessment:** - **Very Low Risk**: Adding a NULL check is the most conservative possible fix - **No behavior change**: If event is valid, same behavior; if NULL, safely skipped - **Cannot cause regressions**: A NULL check cannot break working code - **Isolated to AMD**: Only affects AMD PMU code path, not Intel or other architectures **Affected Subsystem:** - `arch/x86/events/amd/` - AMD Performance Monitoring Unit (PMU) - Mature subsystem, present since v5.19 ### 5. USER IMPACT **Who is affected:** - All AMD CPU users running performance monitoring (`perf`) - Enterprise users, cloud providers with AMD servers - Developers using perf for profiling **Severity:** - **Kernel crash (oops)** - System becomes unstable or halts - Reproducible via syzkaller, meaning users can hit this in real workloads **Trigger conditions:** - Using perf events on AMD CPUs - High frequency of events causing throttling - SMP systems with IPI-based event functions ### 6. STABILITY INDICATORS | Indicator | Status | |-----------|--------| | Tested by syzkaller | Yes (reported and reproduced) | | Maintainer sign-off | Peter Zijlstra (top perf maintainer) | | Tested-by tag | Not present | | Time in mainline | In v6.18-rc1/v6.18 | ### 7. DEPENDENCY CHECK **Dependencies:** None - The fix is self-contained - Does not require any other patches - The affected function `amd_pmu_enable_all()` exists in all kernels since v5.19 **Original buggy commit:** - `ada543459cab7f` "perf/x86/amd: Add AMD Fam19h Branch Sampling support" (March 2022) - Present in v5.19 and later - All stable trees from 5.19+ are affected **Backport feasibility:** - Clean apply expected - the code structure is unchanged - The `for_each_set_bit` macro and surrounding code are stable - Minor adjustment may be needed for `x86_pmu.cntr_mask` vs older API ### 8. HISTORICAL CONTEXT The original bug was introduced in commit `ada543459cab7f` dated April 2022 (v5.19-rc1), when the `amd_pmu_enable_all()` function was added as part of AMD Branch Sampling support. The race condition has been latent since then, only now caught by syzkaller fuzzing. ### 9. SUMMARY | Criterion | Verdict | |-----------|---------| | Fixes real bug | ✅ Yes - NULL pointer dereference crash | | Affects users | ✅ Yes - Any AMD perf user | | Small and contained | ✅ Yes - 6 lines, 1 file | | Obviously correct | ✅ Yes - Simple NULL check | | No new features | ✅ Yes - Pure bug fix | | Low regression risk | ✅ Yes - Cannot break anything | | No dependencies | ✅ Yes - Self-contained | | Maintainer approved | ✅ Yes - Peter Zijlstra signed | ### CONCLUSION This commit **should be backported** to stable kernel trees. It fixes a real, reproducible kernel crash (GPF/oops) caused by a NULL pointer dereference in AMD PMU code. The fix is minimal (6 lines), obviously correct (simple NULL check), and carries essentially zero regression risk. The bug affects all AMD users running perf since kernel v5.19. The lack of explicit `Cc: stable(a)vger.kernel.org` and `Fixes:` tags appears to be an oversight given the clear bug-fix nature of this commit. The fix meets all stable kernel criteria: 1. Obviously correct and tested (syzkaller) 2. Fixes a real bug that affects users (kernel crash) 3. Fixes an important issue (system crash) 4. Small and contained (6 lines in 1 file) 5. Does not introduce new features **YES** arch/x86/events/amd/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index b20661b8621d1..8868f5f5379ba 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -763,7 +763,12 @@ static void amd_pmu_enable_all(int added) if (!test_bit(idx, cpuc->active_mask)) continue; - amd_pmu_enable_event(cpuc->events[idx]); + /* + * FIXME: cpuc->events[idx] can become NULL in a subtle race + * condition with NMI->throttle->x86_pmu_stop(). + */ + if (cpuc->events[idx]) + amd_pmu_enable_event(cpuc->events[idx]); } } -- 2.51.0

10 hours, 19 minutes

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[PATCH] hwmon: (dell-smm): Fix off-by-one error in dell_smm_is_visible()

by Armin Wolf

The documentation states that on machines supporting only global fan mode control, the pwmX_enable attributes should only be created for the first fan channel (pwm1_enable, aka channel 0). Fix the off-by-one error caused by the fact that fan channels have a zero-based index. Cc: stable(a)vger.kernel.org Fixes: 1c1658058c99 ("hwmon: (dell-smm) Add support for automatic fan mode") Signed-off-by: Armin Wolf <W_Armin(a)gmx.de> --- drivers/hwmon/dell-smm-hwmon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c index 683baf361c4c..a34753fc2973 100644 --- a/drivers/hwmon/dell-smm-hwmon.c +++ b/drivers/hwmon/dell-smm-hwmon.c @@ -861,9 +861,9 @@ static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types if (auto_fan) { /* * The setting affects all fans, so only create a - * single attribute. + * single attribute for the first fan channel. */ - if (channel != 1) + if (channel != 0) return 0; /* -- 2.39.5

10 hours, 27 minutes

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Bug: Performance regression in 1013af4f585f: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race

by Uschakow, Stanislav

Hello. We have observed a huge latency increase using `fork()` after ingesting the CVE-2025-38085 fix which leads to the commit `1013af4f585f: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race`. On large machines with 1.5TB of memory with 196 cores, we identified mmapping of 1.2TB of shared memory and forking itself dozens or hundreds of times we see a increase of execution times of a factor of 4. The reproducer is at the end of the email. Comparing the a kernel without this patch with a kernel with this patch applied when spawning 1000 children we see those execution times: Patched kernel: $ time make stress ... real 0m11.275s user 0m0.177s sys 0m23.905s Original kernel : $ time make stress ...real 0m2.475s user 0m1.398s sys 0m2.501s The patch in question: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… My observation/assumption is: each child touches 100 random pages and despawns on each despawn `huge_pmd_unshare()` is called each call to `huge_pmd_unshare()` syncrhonizes all threads using `tlb_remove_table_sync_one()` leading to the regression I'm happy to provide more information. Thank you Stanislav Uschakow === Reproducer === Setup: #!/bin/bash echo "Setting up hugepages for reproduction..." # hugepages (1.2TB / 2MB = 614400 pages) REQUIRED_PAGES=614400 # Check current hugepage allocation CURRENT_PAGES=$(cat /proc/sys/vm/nr_hugepages) echo "Current hugepages: $CURRENT_PAGES" if [ "$CURRENT_PAGES" -lt "$REQUIRED_PAGES" ]; then echo "Allocating $REQUIRED_PAGES hugepages..." echo $REQUIRED_PAGES | sudo tee /proc/sys/vm/nr_hugepages ALLOCATED=$(cat /proc/sys/vm/nr_hugepages) echo "Allocated hugepages: $ALLOCATED" if [ "$ALLOCATED" -lt "$REQUIRED_PAGES" ]; then echo "Warning: Could not allocate all required hugepages" echo "Available: $ALLOCATED, Required: $REQUIRED_PAGES" fi fi echo never | sudo tee /sys/kernel/mm/transparent_hugepage/enabled echo -e "\nHugepage information:" cat /proc/meminfo | grep -i huge echo -e "\nSetup complete. You can now run the reproduction test." Makefile: CXX = gcc CXXFLAGS = -O2 -Wall TARGET = hugepage_repro SOURCE = hugepage_repro.c $(TARGET): $(SOURCE) $(CXX) $(CXXFLAGS) -o $(TARGET) $(SOURCE) clean: rm -f $(TARGET) setup: chmod +x setup_hugepages.sh ./setup_hugepages.sh test: $(TARGET) ./$(TARGET) 20 3 stress: $(TARGET) ./$(TARGET) 1000 1 .PHONY: clean setup test stress hugepage_repro.c: #include <sys/mman.h> #include <sys/wait.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <time.h> #include <stdio.h> #define HUGEPAGE_SIZE (2 * 1024 * 1024) // 2MB #define TOTAL_SIZE (1200ULL * 1024 * 1024 * 1024) // 1.2TB #define NUM_HUGEPAGES (TOTAL_SIZE / HUGEPAGE_SIZE) void* create_hugepage_mapping() { void* addr = mmap(NULL, TOTAL_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0); if (addr == MAP_FAILED) { perror("mmap hugepages failed"); exit(1); } return addr; } void touch_random_pages(void* addr, int num_touches) { char* base = (char*)addr; for (int i = 0; i < num_touches; ++i) { size_t offset = (rand() % NUM_HUGEPAGES) * HUGEPAGE_SIZE; volatile char val = base[offset]; (void)val; } } void child_process(void* shared_mem, int child_id) { struct timespec start, end; clock_gettime(CLOCK_MONOTONIC, &start); touch_random_pages(shared_mem, 100); clock_gettime(CLOCK_MONOTONIC, &end); long duration = (end.tv_sec - start.tv_sec) * 1000000 + (end.tv_nsec - start.tv_nsec) / 1000; printf("Child %d completed in %ld μs\n", child_id, duration); } int main(int argc, char* argv[]) { int num_processes = argc > 1 ? atoi(argv[1]) : 50; int iterations = argc > 2 ? atoi(argv[2]) : 5; printf("Creating %lluGB hugepage mapping...\n", TOTAL_SIZE / (1024*1024*1024)); void* shared_mem = create_hugepage_mapping(); for (int iter = 0; iter < iterations; ++iter) { printf("\nIteration %d: Forking %d processes\n", iter + 1, num_processes); pid_t children[num_processes]; struct timespec iter_start, iter_end; clock_gettime(CLOCK_MONOTONIC, &iter_start); for (int i = 0; i < num_processes; ++i) { pid_t pid = fork(); if (pid == 0) { child_process(shared_mem, i); exit(0); } else if (pid > 0) { children[i] = pid; } } for (int i = 0; i < num_processes; ++i) { waitpid(children[i], NULL, 0); } clock_gettime(CLOCK_MONOTONIC, &iter_end); long iter_duration = (iter_end.tv_sec - iter_start.tv_sec) * 1000 + (iter_end.tv_nsec - iter_start.tv_nsec) / 1000000; printf("Iteration completed in %ld ms\n", iter_duration); } munmap(shared_mem, TOTAL_SIZE); return 0; } Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

11 hours, 3 minutes

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FAILED: patch "[PATCH] KVM: nSVM: Fix and simplify LBR virtualization handling with" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 8a4821412cf2c1429fffa07c012dd150f2edf78c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112059-labrador-contently-dd98@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8a4821412cf2c1429fffa07c012dd150f2edf78c Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosry.ahmed(a)linux.dev> Date: Sat, 8 Nov 2025 00:45:21 +0000 Subject: [PATCH] KVM: nSVM: Fix and simplify LBR virtualization handling with nested The current scheme for handling LBRV when nested is used is very complicated, especially when L1 does not enable LBRV (i.e. does not set LBR_CTL_ENABLE_MASK). To avoid copying LBRs between VMCB01 and VMCB02 on every nested transition, the current implementation switches between using VMCB01 or VMCB02 as the source of truth for the LBRs while L2 is running. If L2 enables LBR, VMCB02 is used as the source of truth. When L2 disables LBR, the LBRs are copied to VMCB01 and VMCB01 is used as the source of truth. This introduces significant complexity, and incorrect behavior in some cases. For example, on a nested #VMEXIT, the LBRs are only copied from VMCB02 to VMCB01 if LBRV is enabled in VMCB01. This is because L2's writes to MSR_IA32_DEBUGCTLMSR to enable LBR are intercepted and propagated to VMCB01 instead of VMCB02. However, LBRV is only enabled in VMCB02 when L2 is running. This means that if L2 enables LBR and exits to L1, the LBRs will not be propagated from VMCB02 to VMCB01, because LBRV is disabled in VMCB01. There is no meaningful difference in CPUID rate in L2 when copying LBRs on every nested transition vs. the current approach, so do the simple and correct thing and always copy LBRs between VMCB01 and VMCB02 on nested transitions (when LBRV is disabled by L1). Drop the conditional LBRs copying in __svm_{enable/disable}_lbrv() as it is now unnecessary. VMCB02 becomes the only source of truth for LBRs when L2 is running, regardless of LBRV being enabled by L1, drop svm_get_lbr_vmcb() and use svm->vmcb directly in its place. Fixes: 1d5a1b5860ed ("KVM: x86: nSVM: correctly virtualize LBR msrs when L2 is running") Cc: stable(a)vger.kernel.org Signed-off-by: Yosry Ahmed <yosry.ahmed(a)linux.dev> Link: https://patch.msgid.link/20251108004524.1600006-4-yosry.ahmed@linux.dev Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index a6443feab252..da6e80b3ac35 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -677,11 +677,10 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12 */ svm_copy_lbrs(vmcb02, vmcb12); vmcb02->save.dbgctl &= ~DEBUGCTL_RESERVED_BITS; - svm_update_lbrv(&svm->vcpu); - - } else if (unlikely(vmcb01->control.virt_ext & LBR_CTL_ENABLE_MASK)) { + } else { svm_copy_lbrs(vmcb02, vmcb01); } + svm_update_lbrv(&svm->vcpu); } static inline bool is_evtinj_soft(u32 evtinj) @@ -833,11 +832,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm, svm->soft_int_next_rip = vmcb12_rip; } - vmcb02->control.virt_ext = vmcb01->control.virt_ext & - LBR_CTL_ENABLE_MASK; - if (guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV)) - vmcb02->control.virt_ext |= - (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK); + /* LBR_CTL_ENABLE_MASK is controlled by svm_update_lbrv() */ if (!nested_vmcb_needs_vls_intercept(svm)) vmcb02->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK; @@ -1189,13 +1184,12 @@ int nested_svm_vmexit(struct vcpu_svm *svm) kvm_make_request(KVM_REQ_EVENT, &svm->vcpu); if (unlikely(guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) && - (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) { + (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) svm_copy_lbrs(vmcb12, vmcb02); - svm_update_lbrv(vcpu); - } else if (unlikely(vmcb01->control.virt_ext & LBR_CTL_ENABLE_MASK)) { + else svm_copy_lbrs(vmcb01, vmcb02); - svm_update_lbrv(vcpu); - } + + svm_update_lbrv(vcpu); if (vnmi) { if (vmcb02->control.int_ctl & V_NMI_BLOCKING_MASK) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 53201f13a43c..10c21e4c5406 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -808,13 +808,7 @@ void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb) static void __svm_enable_lbrv(struct kvm_vcpu *vcpu) { - struct vcpu_svm *svm = to_svm(vcpu); - - svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK; - - /* Move the LBR msrs to the vmcb02 so that the guest can see them. */ - if (is_guest_mode(vcpu)) - svm_copy_lbrs(svm->vmcb, svm->vmcb01.ptr); + to_svm(vcpu)->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK; } void svm_enable_lbrv(struct kvm_vcpu *vcpu) @@ -825,35 +819,15 @@ void svm_enable_lbrv(struct kvm_vcpu *vcpu) static void __svm_disable_lbrv(struct kvm_vcpu *vcpu) { - struct vcpu_svm *svm = to_svm(vcpu); - KVM_BUG_ON(sev_es_guest(vcpu->kvm), vcpu->kvm); - svm->vmcb->control.virt_ext &= ~LBR_CTL_ENABLE_MASK; - - /* - * Move the LBR msrs back to the vmcb01 to avoid copying them - * on nested guest entries. - */ - if (is_guest_mode(vcpu)) - svm_copy_lbrs(svm->vmcb01.ptr, svm->vmcb); -} - -static struct vmcb *svm_get_lbr_vmcb(struct vcpu_svm *svm) -{ - /* - * If LBR virtualization is disabled, the LBR MSRs are always kept in - * vmcb01. If LBR virtualization is enabled and L1 is running VMs of - * its own, the MSRs are moved between vmcb01 and vmcb02 as needed. - */ - return svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK ? svm->vmcb : - svm->vmcb01.ptr; + to_svm(vcpu)->vmcb->control.virt_ext &= ~LBR_CTL_ENABLE_MASK; } void svm_update_lbrv(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); bool current_enable_lbrv = svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK; - bool enable_lbrv = (svm_get_lbr_vmcb(svm)->save.dbgctl & DEBUGCTLMSR_LBR) || + bool enable_lbrv = (svm->vmcb->save.dbgctl & DEBUGCTLMSR_LBR) || (is_guest_mode(vcpu) && guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) && (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK)); @@ -2733,19 +2707,19 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = svm->tsc_aux; break; case MSR_IA32_DEBUGCTLMSR: - msr_info->data = svm_get_lbr_vmcb(svm)->save.dbgctl; + msr_info->data = svm->vmcb->save.dbgctl; break; case MSR_IA32_LASTBRANCHFROMIP: - msr_info->data = svm_get_lbr_vmcb(svm)->save.br_from; + msr_info->data = svm->vmcb->save.br_from; break; case MSR_IA32_LASTBRANCHTOIP: - msr_info->data = svm_get_lbr_vmcb(svm)->save.br_to; + msr_info->data = svm->vmcb->save.br_to; break; case MSR_IA32_LASTINTFROMIP: - msr_info->data = svm_get_lbr_vmcb(svm)->save.last_excp_from; + msr_info->data = svm->vmcb->save.last_excp_from; break; case MSR_IA32_LASTINTTOIP: - msr_info->data = svm_get_lbr_vmcb(svm)->save.last_excp_to; + msr_info->data = svm->vmcb->save.last_excp_to; break; case MSR_VM_HSAVE_PA: msr_info->data = svm->nested.hsave_msr; @@ -3013,10 +2987,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) if (data & DEBUGCTL_RESERVED_BITS) return 1; - if (svm_get_lbr_vmcb(svm)->save.dbgctl == data) + if (svm->vmcb->save.dbgctl == data) break; - svm_get_lbr_vmcb(svm)->save.dbgctl = data; + svm->vmcb->save.dbgctl = data; vmcb_mark_dirty(svm->vmcb, VMCB_LBR); svm_update_lbrv(vcpu); break;

12 hours, 6 minutes

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[to-be-updated] mm-kasan-fix-incorrect-unpoisoning-in-vrealloc-for-kasan.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/kasan: fix incorrect unpoisoning in vrealloc for KASAN has been removed from the -mm tree. Its filename was mm-kasan-fix-incorrect-unpoisoning-in-vrealloc-for-kasan.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Jiayuan Chen <jiayuan.chen(a)linux.dev> Subject: mm/kasan: fix incorrect unpoisoning in vrealloc for KASAN Date: Fri, 28 Nov 2025 19:15:14 +0800 Syzkaller reported a memory out-of-bounds bug [1]. This patch fixes two issues: 1. In vrealloc, we were missing the KASAN_VMALLOC_VM_ALLOC flag when unpoisoning the extended region. This flag is required to correctly associate the allocation with KASAN's vmalloc tracking. Note: In contrast, vzalloc (via __vmalloc_node_range_noprof) explicitly sets KASAN_VMALLOC_VM_ALLOC and calls kasan_unpoison_vmalloc() with it. vrealloc must behave consistently �� especially when reusing existing vmalloc regions �� to ensure KASAN can track allocations correctly. 2. When vrealloc reuses an existing vmalloc region (without allocating new pages), KASAN previously generated a new tag, which broke tag-based memory access tracking. We now add a 'reuse_tag' parameter to __kasan_unpoison_vmalloc() to preserve the original tag in such cases. A new helper kasan_unpoison_vralloc() is introduced to handle this reuse scenario, ensuring consistent tag behavior during reallocation. Link: https://lkml.kernel.org/r/20251128111516.244497-1-jiayuan.chen@linux.dev Link: https://syzkaller.appspot.com/bug?extid=997752115a851cb0cf36 [1] Fixes: a0309faf1cb0 ("mm: vmalloc: support more granular vrealloc() sizing") Signed-off-by: Jiayuan Chen <jiayuan.chen(a)linux.dev> Reported-by: syzbot+997752115a851cb0cf36(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68e243a2.050a0220.1696c6.007d.GAE@google.com/T/ Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Danilo Krummrich <dakr(a)kernel.org> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Kees Cook <kees(a)kernel.org> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/kasan.h | 21 +++++++++++++++++++-- mm/kasan/hw_tags.c | 4 ++-- mm/kasan/shadow.c | 6 ++++-- mm/vmalloc.c | 4 ++-- 4 files changed, 27 insertions(+), 8 deletions(-) --- a/include/linux/kasan.h~mm-kasan-fix-incorrect-unpoisoning-in-vrealloc-for-kasan +++ a/include/linux/kasan.h @@ -596,13 +596,23 @@ static inline void kasan_release_vmalloc #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, - kasan_vmalloc_flags_t flags); + kasan_vmalloc_flags_t flags, bool reuse_tag); + +static __always_inline void *kasan_unpoison_vrealloc(const void *start, + unsigned long size, + kasan_vmalloc_flags_t flags) +{ + if (kasan_enabled()) + return __kasan_unpoison_vmalloc(start, size, flags, true); + return (void *)start; +} + static __always_inline void *kasan_unpoison_vmalloc(const void *start, unsigned long size, kasan_vmalloc_flags_t flags) { if (kasan_enabled()) - return __kasan_unpoison_vmalloc(start, size, flags); + return __kasan_unpoison_vmalloc(start, size, flags, false); return (void *)start; } @@ -629,6 +639,13 @@ static inline void kasan_release_vmalloc unsigned long free_region_end, unsigned long flags) { } +static inline void *kasan_unpoison_vrealloc(const void *start, + unsigned long size, + kasan_vmalloc_flags_t flags) +{ + return (void *)start; +} + static inline void *kasan_unpoison_vmalloc(const void *start, unsigned long size, kasan_vmalloc_flags_t flags) --- a/mm/kasan/hw_tags.c~mm-kasan-fix-incorrect-unpoisoning-in-vrealloc-for-kasan +++ a/mm/kasan/hw_tags.c @@ -317,7 +317,7 @@ static void init_vmalloc_pages(const voi } void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, - kasan_vmalloc_flags_t flags) + kasan_vmalloc_flags_t flags, bool reuse_tag) { u8 tag; unsigned long redzone_start, redzone_size; @@ -361,7 +361,7 @@ void *__kasan_unpoison_vmalloc(const voi return (void *)start; } - tag = kasan_random_tag(); + tag = reuse_tag ? get_tag(start) : kasan_random_tag(); start = set_tag(start, tag); /* Unpoison and initialize memory up to size. */ --- a/mm/kasan/shadow.c~mm-kasan-fix-incorrect-unpoisoning-in-vrealloc-for-kasan +++ a/mm/kasan/shadow.c @@ -625,7 +625,7 @@ void kasan_release_vmalloc(unsigned long } void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, - kasan_vmalloc_flags_t flags) + kasan_vmalloc_flags_t flags, bool reuse_tag) { /* * Software KASAN modes unpoison both VM_ALLOC and non-VM_ALLOC @@ -648,7 +648,9 @@ void *__kasan_unpoison_vmalloc(const voi !(flags & KASAN_VMALLOC_PROT_NORMAL)) return (void *)start; - start = set_tag(start, kasan_random_tag()); + if (!reuse_tag) + start = set_tag(start, kasan_random_tag()); + kasan_unpoison(start, size, false); return (void *)start; } --- a/mm/vmalloc.c~mm-kasan-fix-incorrect-unpoisoning-in-vrealloc-for-kasan +++ a/mm/vmalloc.c @@ -4175,8 +4175,8 @@ void *vrealloc_node_align_noprof(const v * We already have the bytes available in the allocation; use them. */ if (size <= alloced_size) { - kasan_unpoison_vmalloc(p + old_size, size - old_size, - KASAN_VMALLOC_PROT_NORMAL); + kasan_unpoison_vrealloc(p, size, + KASAN_VMALLOC_PROT_NORMAL | KASAN_VMALLOC_VM_ALLOC); /* * No need to zero memory here, as unused memory will have * already been zeroed at initial allocation time or during _ Patches currently in -mm which might be from jiayuan.chen(a)linux.dev are

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