Linux-stable-mirror August 2025

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1331 discussions

[PATCH 1/1] hung_task: fix warnings by enforcing alignment on lock structures

by Lance Yang

From: Lance Yang <lance.yang(a)linux.dev> The blocker tracking mechanism assumes that lock pointers are at least 4-byte aligned to use their lower bits for type encoding. However, as reported by Geert Uytterhoeven, some architectures like m68k only guarantee 2-byte alignment of 32-bit values. This breaks the assumption and causes two related WARN_ON_ONCE checks to trigger. To fix this, enforce a minimum of 4-byte alignment on the core lock structures supported by the blocker tracking mechanism. This ensures the algorithm's alignment assumption now holds true on all architectures. This patch adds __aligned(4) to the definitions of "struct mutex", "struct semaphore", and "struct rw_semaphore", resolving the warnings. Thanks to Geert for bisecting! Reported-by: Geert Uytterhoeven <geert(a)linux-m68k.org> Closes: https://lore.kernel.org/lkml/CAMuHMdW7Ab13DdGs2acMQcix5ObJK0O2dG_Fxzr8_g58R… Fixes: e711faaafbe5 ("hung_task: replace blocker_mutex with encoded blocker") Cc: <stable(a)vger.kernel.org> Signed-off-by: Lance Yang <lance.yang(a)linux.dev> --- include/linux/mutex_types.h | 2 +- include/linux/rwsem.h | 2 +- include/linux/semaphore.h | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/linux/mutex_types.h b/include/linux/mutex_types.h index fdf7f515fde8..de798bfbc4c7 100644 --- a/include/linux/mutex_types.h +++ b/include/linux/mutex_types.h @@ -51,7 +51,7 @@ struct mutex { #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; #endif -}; +} __aligned(4); /* For hung_task blocker tracking, which encodes type in LSBs */ #else /* !CONFIG_PREEMPT_RT */ /* diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index f1aaf676a874..f6ecf4a4710d 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -64,7 +64,7 @@ struct rw_semaphore { #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; #endif -}; +} __aligned(4); /* For hung_task blocker tracking, which encodes type in LSBs */ #define RWSEM_UNLOCKED_VALUE 0UL #define RWSEM_WRITER_LOCKED (1UL << 0) diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h index 89706157e622..ac9b9c87bfb7 100644 --- a/include/linux/semaphore.h +++ b/include/linux/semaphore.h @@ -20,7 +20,7 @@ struct semaphore { #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER unsigned long last_holder; #endif -}; +} __aligned(4); /* For hung_task blocker tracking, which encodes type in LSBs */ #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER #define __LAST_HOLDER_SEMAPHORE_INITIALIZER \ -- 2.49.0

4 months, 1 week

[PATCH 1/1] hung_task: fix warnings caused by unaligned lock pointers

by Lance Yang

From: Lance Yang <lance.yang(a)linux.dev> The blocker tracking mechanism assumes that lock pointers are at least 4-byte aligned to use their lower bits for type encoding. However, as reported by Geert Uytterhoeven, some architectures like m68k only guarantee 2-byte alignment of 32-bit values. This breaks the assumption and causes two related WARN_ON_ONCE checks to trigger. To fix this, the runtime checks are adjusted. The first WARN_ON_ONCE in hung_task_set_blocker() is changed to a simple 'if' that returns silently for unaligned pointers. The second, now-invalid WARN_ON_ONCE in hung_task_clear_blocker() is then removed. Thanks to Geert for bisecting! Reported-by: Geert Uytterhoeven <geert(a)linux-m68k.org> Closes: https://lore.kernel.org/lkml/CAMuHMdW7Ab13DdGs2acMQcix5ObJK0O2dG_Fxzr8_g58R… Fixes: e711faaafbe5 ("hung_task: replace blocker_mutex with encoded blocker") Cc: <stable(a)vger.kernel.org> Signed-off-by: Lance Yang <lance.yang(a)linux.dev> --- include/linux/hung_task.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/include/linux/hung_task.h b/include/linux/hung_task.h index 34e615c76ca5..69640f266a69 100644 --- a/include/linux/hung_task.h +++ b/include/linux/hung_task.h @@ -20,6 +20,10 @@ * always zero. So we can use these bits to encode the specific blocking * type. * + * Note that on architectures like m68k with only 2-byte alignment, the + * blocker tracking mechanism gracefully does nothing for any lock that is + * not 4-byte aligned. + * * Type encoding: * 00 - Blocked on mutex (BLOCKER_TYPE_MUTEX) * 01 - Blocked on semaphore (BLOCKER_TYPE_SEM) @@ -45,7 +49,7 @@ static inline void hung_task_set_blocker(void *lock, unsigned long type) * If the lock pointer matches the BLOCKER_TYPE_MASK, return * without writing anything. */ - if (WARN_ON_ONCE(lock_ptr & BLOCKER_TYPE_MASK)) + if (lock_ptr & BLOCKER_TYPE_MASK) return; WRITE_ONCE(current->blocker, lock_ptr | type); @@ -53,8 +57,6 @@ static inline void hung_task_set_blocker(void *lock, unsigned long type) static inline void hung_task_clear_blocker(void) { - WARN_ON_ONCE(!READ_ONCE(current->blocker)); - WRITE_ONCE(current->blocker, 0UL); } -- 2.49.0

4 months, 1 week

[PATCH v10 1/3] scsi: sd: Fix build warning in sd_revalidate_disk()

by Abinash Singh

A build warning was triggered due to excessive stack usage in sd_revalidate_disk(): drivers/scsi/sd.c: In function ‘sd_revalidate_disk.isra’: drivers/scsi/sd.c:3824:1: warning: the frame size of 1160 bytes is larger than 1024 bytes [-Wframe-larger-than=] This is caused by a large local struct queue_limits (~400B) allocated on the stack. Replacing it with a heap allocation using kmalloc() significantly reduces frame usage. Kernel stack is limited (~8 KB), and allocating large structs on the stack is discouraged. As the function already performs heap allocations (e.g. for buffer), this change fits well. Fixes: 804e498e0496 ("sd: convert to the atomic queue limits API") Cc: stable(a)vger.kernel.org Reviewed-by: Bart Van Assche <bvanassche(a)acm.org> Signed-off-by: Abinash Singh <abinashsinghlalotra(a)gmail.com> --- drivers/scsi/sd.c | 50 ++++++++++++++++++++++++++--------------------- 1 file changed, 28 insertions(+), 22 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 5b8668accf8e..bf12e23f1212 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3696,10 +3696,10 @@ static int sd_revalidate_disk(struct gendisk *disk) struct scsi_disk *sdkp = scsi_disk(disk); struct scsi_device *sdp = sdkp->device; sector_t old_capacity = sdkp->capacity; - struct queue_limits lim; - unsigned char *buffer; + struct queue_limits *lim = NULL; + unsigned char *buffer = NULL; unsigned int dev_max; - int err; + int err = 0; SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_revalidate_disk\n")); @@ -3711,6 +3711,10 @@ static int sd_revalidate_disk(struct gendisk *disk) if (!scsi_device_online(sdp)) goto out; + lim = kmalloc(sizeof(*lim), GFP_KERNEL); + if (!lim) + goto out; + buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL); if (!buffer) { sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory " @@ -3720,14 +3724,14 @@ static int sd_revalidate_disk(struct gendisk *disk) sd_spinup_disk(sdkp); - lim = queue_limits_start_update(sdkp->disk->queue); + *lim = queue_limits_start_update(sdkp->disk->queue); /* * Without media there is no reason to ask; moreover, some devices * react badly if we do. */ if (sdkp->media_present) { - sd_read_capacity(sdkp, &lim, buffer); + sd_read_capacity(sdkp, lim, buffer); /* * Some USB/UAS devices return generic values for mode pages * until the media has been accessed. Trigger a READ operation @@ -3741,17 +3745,17 @@ static int sd_revalidate_disk(struct gendisk *disk) * cause this to be updated correctly and any device which * doesn't support it should be treated as rotational. */ - lim.features |= (BLK_FEAT_ROTATIONAL | BLK_FEAT_ADD_RANDOM); + lim->features |= (BLK_FEAT_ROTATIONAL | BLK_FEAT_ADD_RANDOM); if (scsi_device_supports_vpd(sdp)) { sd_read_block_provisioning(sdkp); - sd_read_block_limits(sdkp, &lim); + sd_read_block_limits(sdkp, lim); sd_read_block_limits_ext(sdkp); - sd_read_block_characteristics(sdkp, &lim); - sd_zbc_read_zones(sdkp, &lim, buffer); + sd_read_block_characteristics(sdkp, lim); + sd_zbc_read_zones(sdkp, lim, buffer); } - sd_config_discard(sdkp, &lim, sd_discard_mode(sdkp)); + sd_config_discard(sdkp, lim, sd_discard_mode(sdkp)); sd_print_capacity(sdkp, old_capacity); @@ -3761,47 +3765,46 @@ static int sd_revalidate_disk(struct gendisk *disk) sd_read_app_tag_own(sdkp, buffer); sd_read_write_same(sdkp, buffer); sd_read_security(sdkp, buffer); - sd_config_protection(sdkp, &lim); + sd_config_protection(sdkp, lim); } /* * We now have all cache related info, determine how we deal * with flush requests. */ - sd_set_flush_flag(sdkp, &lim); + sd_set_flush_flag(sdkp, lim); /* Initial block count limit based on CDB TRANSFER LENGTH field size. */ dev_max = sdp->use_16_for_rw ? SD_MAX_XFER_BLOCKS : SD_DEF_XFER_BLOCKS; /* Some devices report a maximum block count for READ/WRITE requests. */ dev_max = min_not_zero(dev_max, sdkp->max_xfer_blocks); - lim.max_dev_sectors = logical_to_sectors(sdp, dev_max); + lim->max_dev_sectors = logical_to_sectors(sdp, dev_max); if (sd_validate_min_xfer_size(sdkp)) - lim.io_min = logical_to_bytes(sdp, sdkp->min_xfer_blocks); + lim->io_min = logical_to_bytes(sdp, sdkp->min_xfer_blocks); else - lim.io_min = 0; + lim->io_min = 0; /* * Limit default to SCSI host optimal sector limit if set. There may be * an impact on performance for when the size of a request exceeds this * host limit. */ - lim.io_opt = sdp->host->opt_sectors << SECTOR_SHIFT; + lim->io_opt = sdp->host->opt_sectors << SECTOR_SHIFT; if (sd_validate_opt_xfer_size(sdkp, dev_max)) { - lim.io_opt = min_not_zero(lim.io_opt, + lim->io_opt = min_not_zero(lim->io_opt, logical_to_bytes(sdp, sdkp->opt_xfer_blocks)); } sdkp->first_scan = 0; set_capacity_and_notify(disk, logical_to_sectors(sdp, sdkp->capacity)); - sd_config_write_same(sdkp, &lim); - kfree(buffer); + sd_config_write_same(sdkp, lim); - err = queue_limits_commit_update_frozen(sdkp->disk->queue, &lim); + err = queue_limits_commit_update_frozen(sdkp->disk->queue, lim); if (err) - return err; + goto out; /* * Query concurrent positioning ranges after @@ -3820,7 +3823,10 @@ static int sd_revalidate_disk(struct gendisk *disk) set_capacity_and_notify(disk, 0); out: - return 0; + kfree(buffer); + kfree(lim); + + return err; } /** -- 2.43.0

4 months, 1 week

[PATCH net] net: mana: Remove redundant netdev_lock_ops_to_full() calls

by Saurabh Sengar

NET_SHAPER is always selected for MANA driver. When NET_SHAPER is enabled, netdev_lock_ops_to_full() reduces effectively to only an assert for lock, which is always held in the path when NET_SHAPER is enabled. Remove the redundant netdev_lock_ops_to_full() call. Fixes: d5c8f0e4e0cb ("net: mana: Fix potential deadlocks in mana napi ops") Cc: stable(a)vger.kernel.org Signed-off-by: Saurabh Sengar <ssengar(a)linux.microsoft.com> --- drivers/net/ethernet/microsoft/mana/mana_en.c | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 550843e2164b..f0dbf4e82e0b 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -2100,10 +2100,8 @@ static void mana_destroy_txq(struct mana_port_context *apc) napi = &apc->tx_qp[i].tx_cq.napi; if (apc->tx_qp[i].txq.napi_initialized) { napi_synchronize(napi); - netdev_lock_ops_to_full(napi->dev); napi_disable_locked(napi); netif_napi_del_locked(napi); - netdev_unlock_full_to_ops(napi->dev); apc->tx_qp[i].txq.napi_initialized = false; } mana_destroy_wq_obj(apc, GDMA_SQ, apc->tx_qp[i].tx_object); @@ -2256,10 +2254,8 @@ static int mana_create_txq(struct mana_port_context *apc, mana_create_txq_debugfs(apc, i); set_bit(NAPI_STATE_NO_BUSY_POLL, &cq->napi.state); - netdev_lock_ops_to_full(net); netif_napi_add_locked(net, &cq->napi, mana_poll); napi_enable_locked(&cq->napi); - netdev_unlock_full_to_ops(net); txq->napi_initialized = true; mana_gd_ring_cq(cq->gdma_cq, SET_ARM_BIT); @@ -2295,10 +2291,8 @@ static void mana_destroy_rxq(struct mana_port_context *apc, if (napi_initialized) { napi_synchronize(napi); - netdev_lock_ops_to_full(napi->dev); napi_disable_locked(napi); netif_napi_del_locked(napi); - netdev_unlock_full_to_ops(napi->dev); } xdp_rxq_info_unreg(&rxq->xdp_rxq); @@ -2549,18 +2543,14 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc, gc->cq_table[cq->gdma_id] = cq->gdma_cq; - netdev_lock_ops_to_full(ndev); netif_napi_add_weight_locked(ndev, &cq->napi, mana_poll, 1); - netdev_unlock_full_to_ops(ndev); WARN_ON(xdp_rxq_info_reg(&rxq->xdp_rxq, ndev, rxq_idx, cq->napi.napi_id)); WARN_ON(xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq, MEM_TYPE_PAGE_POOL, rxq->page_pool)); - netdev_lock_ops_to_full(ndev); napi_enable_locked(&cq->napi); - netdev_unlock_full_to_ops(ndev); mana_gd_ring_cq(cq->gdma_cq, SET_ARM_BIT); out: -- 2.43.0

4 months, 1 week

[PATCH 5.15.y] wifi: mac80211: check basic rates validity in sta_link_apply_parameters

by Hanne-Lotta Mäenpää

From: Mikhail Lobanov <m.lobanov(a)rosa.ru> [ Upstream commit 16ee3ea8faef8ff042acc15867a6c458c573de61 ] When userspace sets supported rates for a new station via NL80211_CMD_NEW_STATION, it might send a list that's empty or contains only invalid values. Currently, we process these values in sta_link_apply_parameters() without checking the result of ieee80211_parse_bitrates(), which can lead to an empty rates bitmap. A similar issue was addressed for NL80211_CMD_SET_BSS in commit ce04abc3fcc6 ("wifi: mac80211: check basic rates validity"). This patch applies the same approach in sta_link_apply_parameters() for NL80211_CMD_NEW_STATION, ensuring there is at least one valid rate by inspecting the result of ieee80211_parse_bitrates(). Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: b95eb7f0eee4 ("wifi: cfg80211/mac80211: separate link params from station params") Signed-off-by: Mikhail Lobanov <m.lobanov(a)rosa.ru> Link: https://patch.msgid.link/20250317103139.17625-1-m.lobanov@rosa.ru Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> [ Summary of conflict resolutions: - Function ieee80211_parse_bitrates() takes channel width as its first parameter in mainline kernel version. In v5.15 the function takes the whole chandef struct as its first parameter. - The same function takes link station parameters as its last parameter, and in v5.15 they are in a struct called sta, instead of a struct called link_sta. ] Signed-off-by: Hanne-Lotta Mäenpää <hannelotta(a)gmail.com> --- net/mac80211/cfg.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 2b77cb290788..706ff67f4254 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -1658,12 +1658,13 @@ static int sta_apply_parameters(struct ieee80211_local *local, return ret; } - if (params->supported_rates && params->supported_rates_len) { - ieee80211_parse_bitrates(&sdata->vif.bss_conf.chandef, - sband, params->supported_rates, - params->supported_rates_len, - &sta->sta.supp_rates[sband->band]); - } + if (params->supported_rates && + params->supported_rates_len && + !ieee80211_parse_bitrates(&sdata->vif.bss_conf.chandef, + sband, params->supported_rates, + params->supported_rates_len, + &sta->sta.supp_rates[sband->band])) + return -EINVAL; if (params->ht_capa) ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, -- 2.50.0

4 months, 1 week

+ mm-damon-core-set-quota-charged_from-to-jiffies-at-first-charge-window.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: mm/damon/core: set quota->charged_from to jiffies at first charge window has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-core-set-quota-charged_from-to-jiffies-at-first-charge-window.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Sang-Heon Jeon <ekffu200098(a)gmail.com> Subject: mm/damon/core: set quota->charged_from to jiffies at first charge window Date: Fri, 22 Aug 2025 11:50:57 +0900 Kernel initializes the "jiffies" timer as 5 minutes below zero, as shown in include/linux/jiffies.h /* * Have the 32 bit jiffies value wrap 5 minutes after boot * so jiffies wrap bugs show up earlier. */ #define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) And jiffies comparison help functions cast unsigned value to signed to cover wraparound #define time_after_eq(a,b) \ (typecheck(unsigned long, a) && \ typecheck(unsigned long, b) && \ ((long)((a) - (b)) >= 0)) When quota->charged_from is initialized to 0, time_after_eq() can incorrectly return FALSE even after reset_interval has elapsed. This occurs when (jiffies - reset_interval) produces a value with MSB=1, which is interpreted as negative in signed arithmetic. This issue primarily affects 32-bit systems because: On 64-bit systems: MSB=1 values occur after ~292 million years from boot (assuming HZ=1000), almost impossible. On 32-bit systems: MSB=1 values occur during the first 5 minutes after boot, and the second half of every jiffies wraparound cycle, starting from day 25 (assuming HZ=1000) When above unexpected FALSE return from time_after_eq() occurs, the charging window will not reset. The user impact depends on esz value at that time. If esz is 0, scheme ignores configured quotas and runs without any limits. If esz is not 0, scheme stops working once the quota is exhausted. It remains until the charging window finally resets. So, change quota->charged_from to jiffies at damos_adjust_quota() when it is considered as the first charge window. By this change, we can avoid unexpected FALSE return from time_after_eq() Link: https://lkml.kernel.org/r/20250822025057.1740854-1-ekffu200098@gmail.com Fixes: 2b8a248d5873 ("mm/damon/schemes: implement size quota for schemes application speed control") # 5.16 Signed-off-by: Sang-Heon Jeon <ekffu200098(a)gmail.com> Reviewed-by: SeongJae Park <sj(a)kernel.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/damon/core.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/damon/core.c~mm-damon-core-set-quota-charged_from-to-jiffies-at-first-charge-window +++ a/mm/damon/core.c @@ -2111,6 +2111,10 @@ static void damos_adjust_quota(struct da if (!quota->ms && !quota->sz && list_empty(&quota->goals)) return; + /* First charge window */ + if (!quota->total_charged_sz && !quota->charged_from) + quota->charged_from = jiffies; + /* New charge window starts */ if (time_after_eq(jiffies, quota->charged_from + msecs_to_jiffies(quota->reset_interval))) { _ Patches currently in -mm which might be from ekffu200098(a)gmail.com are mm-damon-core-set-quota-charged_from-to-jiffies-at-first-charge-window.patch mm-damon-update-expired-description-of-damos_action.patch docs-mm-damon-design-fix-typo-s-sz_trtied-sz_tried.patch selftests-damon-test-no-op-commit-broke-damon-status.patch selftests-damon-test-no-op-commit-broke-damon-status-fix.patch mm-damon-tests-core-kunit-add-damos_commit_filter-test.patch

4 months, 1 week

+ mm-hugetlb-add-missing-hugetlb_lock-in-__unmap_hugepage_range.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: mm/hugetlb: add missing hugetlb_lock in __unmap_hugepage_range() has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-hugetlb-add-missing-hugetlb_lock-in-__unmap_hugepage_range.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Jeongjun Park <aha310510(a)gmail.com> Subject: mm/hugetlb: add missing hugetlb_lock in __unmap_hugepage_range() Date: Sun, 24 Aug 2025 03:21:15 +0900 When restoring a reservation for an anonymous page, we need to check to freeing a surplus. However, __unmap_hugepage_range() causes data race because it reads h->surplus_huge_pages without the protection of hugetlb_lock. And adjust_reservation is a boolean variable that indicates whether reservations for anonymous pages in each folio should be restored. Therefore, it should be initialized to false for each round of the loop. However, this variable is not initialized to false except when defining the current adjust_reservation variable. This means that once adjust_reservation is set to true even once within the loop, reservations for anonymous pages will be restored unconditionally in all subsequent rounds, regardless of the folio's state. To fix this, we need to add the missing hugetlb_lock, unlock the page_table_lock earlier so that we don't lock the hugetlb_lock inside the page_table_lock lock, and initialize adjust_reservation to false on each round within the loop. Link: https://lkml.kernel.org/r/20250823182115.1193563-1-aha310510@gmail.com Fixes: df7a6d1f6405 ("mm/hugetlb: restore the reservation if needed") Signed-off-by: Jeongjun Park <aha310510(a)gmail.com> Reported-by: syzbot+417aeb05fd190f3a6da9(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=417aeb05fd190f3a6da9 Cc: Breno Leitao <leitao(a)debian.org> Cc: David Hildenbrand <david(a)redhat.com> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/hugetlb.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/mm/hugetlb.c~mm-hugetlb-add-missing-hugetlb_lock-in-__unmap_hugepage_range +++ a/mm/hugetlb.c @@ -5851,7 +5851,7 @@ void __unmap_hugepage_range(struct mmu_g spinlock_t *ptl; struct hstate *h = hstate_vma(vma); unsigned long sz = huge_page_size(h); - bool adjust_reservation = false; + bool adjust_reservation; unsigned long last_addr_mask; bool force_flush = false; @@ -5944,6 +5944,7 @@ void __unmap_hugepage_range(struct mmu_g sz); hugetlb_count_sub(pages_per_huge_page(h), mm); hugetlb_remove_rmap(folio); + spin_unlock(ptl); /* * Restore the reservation for anonymous page, otherwise the @@ -5951,14 +5952,16 @@ void __unmap_hugepage_range(struct mmu_g * If there we are freeing a surplus, do not set the restore * reservation bit. */ + adjust_reservation = false; + + spin_lock_irq(&hugetlb_lock); if (!h->surplus_huge_pages && __vma_private_lock(vma) && folio_test_anon(folio)) { folio_set_hugetlb_restore_reserve(folio); /* Reservation to be adjusted after the spin lock */ adjust_reservation = true; } - - spin_unlock(ptl); + spin_unlock_irq(&hugetlb_lock); /* * Adjust the reservation for the region that will have the _ Patches currently in -mm which might be from aha310510(a)gmail.com are mm-hugetlb-add-missing-hugetlb_lock-in-__unmap_hugepage_range.patch

4 months, 1 week

+ kexec-arm64-initialize-the-random-field-of-kbuf-to-zero-in-the-image-loader.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: kexec/arm64: initialize the random field of kbuf to zero in the image loader has been added to the -mm mm-hotfixes-unstable branch. Its filename is kexec-arm64-initialize-the-random-field-of-kbuf-to-zero-in-the-image-loader.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Breno Leitao <leitao(a)debian.org> Subject: kexec/arm64: initialize the random field of kbuf to zero in the image loader Date: Thu Aug 21 04:11:21 2025 -0700 Add an explicit initialization for the random member of the kbuf structure within the image_load function in arch/arm64/kernel/kexec_image.c. Setting kbuf.random to zero ensures a deterministic and clean starting state for the buffer used during kernel image loading, avoiding this UBSAN issue later, when kbuf.random is read. [ 32.362488] UBSAN: invalid-load in ./include/linux/kexec.h:210:10 [ 32.362649] load of value 252 is not a valid value for type '_Bool' Link: https://lkml.kernel.org/r/oninomspajhxp4omtdapxnckxydbk2nzmrix7rggmpukpnzad… Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly Signed-off-by: Breno Leitao <leitao(a)debian.org> Cc: Baoquan He <bhe(a)redhat.com> Cc: Coiby Xu <coxu(a)redhat.com> Cc: "Daniel P. Berrange" <berrange(a)redhat.com> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: Dave Young <dyoung(a)redhat.com> Cc: Kairui Song <ryncsn(a)gmail.com> Cc: Liu Pingfan <kernelfans(a)gmail.com> Cc: Milan Broz <gmazyland(a)gmail.com> Cc: Ondrej Kozina <okozina(a)redhat.com> Cc: Vitaly Kuznetsov <vkuznets(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/arm64/kernel/kexec_image.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/arm64/kernel/kexec_image.c~kexec-arm64-initialize-the-random-field-of-kbuf-to-zero-in-the-image-loader +++ a/arch/arm64/kernel/kexec_image.c @@ -76,6 +76,7 @@ static void *image_load(struct kimage *i kbuf.buf_min = 0; kbuf.buf_max = ULONG_MAX; kbuf.top_down = false; + kbuf.random = 0; kbuf.buffer = kernel; kbuf.bufsz = kernel_len; _ Patches currently in -mm which might be from leitao(a)debian.org are kexec-arm64-initialize-the-random-field-of-kbuf-to-zero-in-the-image-loader.patch

4 months, 1 week

[PATCH] net/dccp: validate Reset/Close/CloseReq in DCCP_REQUESTING

by Yizhou Zhao

DCCP sockets in DCCP_REQUESTING state do not check the sequence number or acknowledgment number for incoming Reset, CloseReq, and Close packets. As a result, an attacker can send a spoofed Reset packet while the client is in the requesting state. The client will accept the packet without verification and immediately close the connection, causing a denial of service (DoS) attack. This patch moves the processing of Reset, Close, and CloseReq packets into dccp_rcv_request_sent_state_process() and validates the ack number before accepting them. This fix should apply to stable versions *only* in Linux 5.x and 6.x. Note that DCCP was removed in Linux 6.16, so this patch is only relevant for older versions. We tested it on Ubuntu 24.04 LTS (Linux 6.8) and it worked as expected. Signed-off-by: Yizhou Zhao <zhaoyz24(a)mails.tsinghua.edu.cn> Cc: stable(a)vger.kernel.org Signed-off-by: Yizhou Zhao <zhaoyz24(a)mails.tsinghua.edu.cn> --- net/dccp/input.c | 54 ++++++++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 22 deletions(-) diff --git a/net/dccp/input.c b/net/dccp/input.c index 2cbb757a8..0b1ffb044 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -397,21 +397,22 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, * / * Response processing continues in Step 10; Reset * processing continues in Step 9 * / */ + struct dccp_sock *dp = dccp_sk(sk); + + if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, + dp->dccps_awl, dp->dccps_awh)) { + dccp_pr_debug("invalid ackno: S.AWL=%llu, " + "P.ackno=%llu, S.AWH=%llu\n", + (unsigned long long)dp->dccps_awl, + (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, + (unsigned long long)dp->dccps_awh); + goto out_invalid_packet; + } + if (dh->dccph_type == DCCP_PKT_RESPONSE) { const struct inet_connection_sock *icsk = inet_csk(sk); - struct dccp_sock *dp = dccp_sk(sk); - long tstamp = dccp_timestamp(); - - if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, - dp->dccps_awl, dp->dccps_awh)) { - dccp_pr_debug("invalid ackno: S.AWL=%llu, " - "P.ackno=%llu, S.AWH=%llu\n", - (unsigned long long)dp->dccps_awl, - (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, - (unsigned long long)dp->dccps_awh); - goto out_invalid_packet; - } + long tstamp = dccp_timestamp(); /* * If option processing (Step 8) failed, return 1 here so that * dccp_v4_do_rcv() sends a Reset. The Reset code depends on @@ -496,6 +497,13 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, } dccp_send_ack(sk); return -1; + } else if (dh->dccph_type == DCCP_PKT_RESET) { + dccp_rcv_reset(sk, skb); + return 0; + } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { + return dccp_rcv_closereq(sk, skb); + } else if (dh->dccph_type == DCCP_PKT_CLOSE) { + return dccp_rcv_close(sk, skb); } out_invalid_packet: @@ -658,17 +666,19 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, * Set TIMEWAIT timer * Drop packet and return */ - if (dh->dccph_type == DCCP_PKT_RESET) { - dccp_rcv_reset(sk, skb); - return 0; - } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */ - if (dccp_rcv_closereq(sk, skb)) - return 0; - goto discard; - } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */ - if (dccp_rcv_close(sk, skb)) + if (sk->sk_state != DCCP_REQUESTING) { + if (dh->dccph_type == DCCP_PKT_RESET) { + dccp_rcv_reset(sk, skb); return 0; - goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */ + if (dccp_rcv_closereq(sk, skb)) + return 0; + goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */ + if (dccp_rcv_close(sk, skb)) + return 0; + goto discard; + } } switch (sk->sk_state) { -- 2.34.1

4 months, 1 week

[PATCH] net/dccp: validate Reset/Close/CloseReq in DCCP_REQUESTING

by Yizhou Zhao

DCCP sockets in DCCP_REQUESTING state do not check the sequence number or acknowledgment number for incoming Reset, CloseReq, and Close packets. As a result, an attacker can send a spoofed Reset packet while the client is in the requesting state. The client will accept the packet without verification and immediately close the connection, causing a denial of service (DoS) attack. This patch moves the processing of Reset, Close, and CloseReq packets into dccp_rcv_request_sent_state_process() and validates the ack number before accepting them. This fix should apply to Linux 5.x and 6.x, including stable versions. Note that DCCP was removed in Linux 6.16, so this patch is only relevant for older versions. We tested it on Ubuntu 24.04 LTS (Linux 6.8) and it worked as expected. Signed-off-by: Yizhou Zhao <zhaoyz24(a)mails.tsinghua.edu.cn> Cc: stable(a)vger.kernel.org --- net/dccp/input.c | 54 ++++++++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 22 deletions(-) diff --git a/net/dccp/input.c b/net/dccp/input.c index 2cbb757a8..0b1ffb044 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -397,21 +397,22 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, * / * Response processing continues in Step 10; Reset * processing continues in Step 9 * / */ + struct dccp_sock *dp = dccp_sk(sk); + + if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, + dp->dccps_awl, dp->dccps_awh)) { + dccp_pr_debug("invalid ackno: S.AWL=%llu, " + "P.ackno=%llu, S.AWH=%llu\n", + (unsigned long long)dp->dccps_awl, + (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, + (unsigned long long)dp->dccps_awh); + goto out_invalid_packet; + } + if (dh->dccph_type == DCCP_PKT_RESPONSE) { const struct inet_connection_sock *icsk = inet_csk(sk); - struct dccp_sock *dp = dccp_sk(sk); - long tstamp = dccp_timestamp(); - - if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, - dp->dccps_awl, dp->dccps_awh)) { - dccp_pr_debug("invalid ackno: S.AWL=%llu, " - "P.ackno=%llu, S.AWH=%llu\n", - (unsigned long long)dp->dccps_awl, - (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, - (unsigned long long)dp->dccps_awh); - goto out_invalid_packet; - } + long tstamp = dccp_timestamp(); /* * If option processing (Step 8) failed, return 1 here so that * dccp_v4_do_rcv() sends a Reset. The Reset code depends on @@ -496,6 +497,13 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, } dccp_send_ack(sk); return -1; + } else if (dh->dccph_type == DCCP_PKT_RESET) { + dccp_rcv_reset(sk, skb); + return 0; + } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { + return dccp_rcv_closereq(sk, skb); + } else if (dh->dccph_type == DCCP_PKT_CLOSE) { + return dccp_rcv_close(sk, skb); } out_invalid_packet: @@ -658,17 +666,19 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, * Set TIMEWAIT timer * Drop packet and return */ - if (dh->dccph_type == DCCP_PKT_RESET) { - dccp_rcv_reset(sk, skb); - return 0; - } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */ - if (dccp_rcv_closereq(sk, skb)) - return 0; - goto discard; - } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */ - if (dccp_rcv_close(sk, skb)) + if (sk->sk_state != DCCP_REQUESTING) { + if (dh->dccph_type == DCCP_PKT_RESET) { + dccp_rcv_reset(sk, skb); return 0; - goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */ + if (dccp_rcv_closereq(sk, skb)) + return 0; + goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */ + if (dccp_rcv_close(sk, skb)) + return 0; + goto discard; + } } switch (sk->sk_state) { -- 2.34.1

4 months, 1 week

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