From 02e36a9d84665d3606557f436ee56c98c519f91f Mon Sep 17 00:00:00 2001 From: CIQ Kernel Automation Date: Thu, 30 Apr 2026 07:07:32 +0000 Subject: [PATCH 1/6] mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats jira VULN-173889 cve CVE-2025-68800 commit-author Ido Schimmel commit 8ac1dacec458f55f871f7153242ed6ab60373b90 Cited commit added a dedicated mutex (instead of RTNL) to protect the multicast route list, so that it will not change while the driver periodically traverses it in order to update the kernel about multicast route stats that were queried from the device. One instance of list entry deletion (during route replace) was missed and it can result in a use-after-free [1]. Fix by acquiring the mutex before deleting the entry from the list and releasing it afterwards. [1] BUG: KASAN: slab-use-after-free in mlxsw_sp_mr_stats_update+0x4a5/0x540 drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:1006 [mlxsw_spectrum] Read of size 8 at addr ffff8881523c2fa8 by task kworker/2:5/22043 CPU: 2 UID: 0 PID: 22043 Comm: kworker/2:5 Not tainted 6.18.0-rc1-custom-g1a3d6d7cd014 #1 PREEMPT(full) Hardware name: Mellanox Technologies Ltd. MSN2010/SA002610, BIOS 5.6.5 08/24/2017 Workqueue: mlxsw_core mlxsw_sp_mr_stats_update [mlxsw_spectrum] Call Trace: dump_stack_lvl+0xba/0x110 print_report+0x174/0x4f5 kasan_report+0xdf/0x110 mlxsw_sp_mr_stats_update+0x4a5/0x540 drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:1006 [mlxsw_spectrum] process_one_work+0x9cc/0x18e0 worker_thread+0x5df/0xe40 kthread+0x3b8/0x730 ret_from_fork+0x3e9/0x560 ret_from_fork_asm+0x1a/0x30 Allocated by task 29933: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 mlxsw_sp_mr_route_add+0xd8/0x4770 [mlxsw_spectrum] mlxsw_sp_router_fibmr_event_work+0x371/0xad0 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:7965 [mlxsw_spectrum] process_one_work+0x9cc/0x18e0 worker_thread+0x5df/0xe40 kthread+0x3b8/0x730 ret_from_fork+0x3e9/0x560 ret_from_fork_asm+0x1a/0x30 Freed by task 29933: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_save_free_info+0x3b/0x70 __kasan_slab_free+0x43/0x70 kfree+0x14e/0x700 mlxsw_sp_mr_route_add+0x2dea/0x4770 drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:444 [mlxsw_spectrum] mlxsw_sp_router_fibmr_event_work+0x371/0xad0 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:7965 [mlxsw_spectrum] process_one_work+0x9cc/0x18e0 worker_thread+0x5df/0xe40 kthread+0x3b8/0x730 ret_from_fork+0x3e9/0x560 ret_from_fork_asm+0x1a/0x30 Fixes: f38656d06725 ("mlxsw: spectrum_mr: Protect multicast route list with a lock") Signed-off-by: Ido Schimmel Reviewed-by: Petr Machata Signed-off-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/f996feecfd59fde297964bfc85040b6d83ec6089.1764695650.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski (cherry picked from commit 8ac1dacec458f55f871f7153242ed6ab60373b90) Signed-off-by: CIQ Kernel Automation --- drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c index 1f6bc0c7e91dd..c39aca54a0d6b 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c @@ -440,7 +440,9 @@ int mlxsw_sp_mr_route_add(struct mlxsw_sp_mr_table *mr_table, rhashtable_remove_fast(&mr_table->route_ht, &mr_orig_route->ht_node, mlxsw_sp_mr_route_ht_params); + mutex_lock(&mr_table->route_list_lock); list_del(&mr_orig_route->node); + mutex_unlock(&mr_table->route_list_lock); mlxsw_sp_mr_route_destroy(mr_table, mr_orig_route); } From 0f455486dd81b0948b49cac5ebb469da82a4e4bc Mon Sep 17 00:00:00 2001 From: CIQ Kernel Automation Date: Thu, 30 Apr 2026 07:08:12 +0000 Subject: [PATCH 2/6] mm/damon/sysfs: cleanup attrs subdirs on context dir setup failure jira VULN-176247 cve CVE-2026-23144 commit-author SeongJae Park commit 9814cc832b88bd040fc2a1817c2b5469d0f7e862 When a context DAMON sysfs directory setup is failed after setup of attrs/ directory, subdirectories of attrs/ directory are not cleaned up. As a result, DAMON sysfs interface is nearly broken until the system reboots, and the memory for the unremoved directory is leaked. Cleanup the directories under such failures. Link: https://lkml.kernel.org/r/20251225023043.18579-3-sj@kernel.org Fixes: c951cd3b8901 ("mm/damon: implement a minimal stub for sysfs-based DAMON interface") Signed-off-by: SeongJae Park Cc: chongjiapeng Cc: # 5.18.x Signed-off-by: Andrew Morton (cherry picked from commit 9814cc832b88bd040fc2a1817c2b5469d0f7e862) Signed-off-by: CIQ Kernel Automation --- mm/damon/sysfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 07e5f1bdf025f..f839406cc091f 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -1772,7 +1772,7 @@ static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context) err = damon_sysfs_context_set_targets(context); if (err) - goto put_attrs_out; + goto rmdir_put_attrs_out; err = damon_sysfs_context_set_schemes(context); if (err) @@ -1782,7 +1782,8 @@ static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context) put_targets_attrs_out: kobject_put(&context->targets->kobj); context->targets = NULL; -put_attrs_out: +rmdir_put_attrs_out: + damon_sysfs_attrs_rm_dirs(context->attrs); kobject_put(&context->attrs->kobj); context->attrs = NULL; return err; From b2c3b6600a39591231121de86997cdd68f83a3b8 Mon Sep 17 00:00:00 2001 From: CIQ Kernel Automation Date: Thu, 30 Apr 2026 07:08:39 +0000 Subject: [PATCH 3/6] scsi: target: iscsi: Fix use-after-free in iscsit_dec_session_usage_count() jira VULN-176314 cve CVE-2026-23193 commit-author Maurizio Lombardi commit 84dc6037390b8607c5551047d3970336cb51ba9a In iscsit_dec_session_usage_count(), the function calls complete() while holding the sess->session_usage_lock. Similar to the connection usage count logic, the waiter signaled by complete() (e.g., in the session release path) may wake up and free the iscsit_session structure immediately. This creates a race condition where the current thread may attempt to execute spin_unlock_bh() on a session structure that has already been deallocated, resulting in a KASAN slab-use-after-free. To resolve this, release the session_usage_lock before calling complete() to ensure all dereferences of the sess pointer are finished before the waiter is allowed to proceed with deallocation. Signed-off-by: Maurizio Lombardi Reported-by: Zhaojuan Guo Reviewed-by: Mike Christie Link: https://patch.msgid.link/20260112165352.138606-3-mlombard@redhat.com Signed-off-by: Martin K. Petersen (cherry picked from commit 84dc6037390b8607c5551047d3970336cb51ba9a) Signed-off-by: CIQ Kernel Automation --- drivers/target/iscsi/iscsi_target_util.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 31c64cf25ac1c..c87955cf97a07 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -785,8 +785,11 @@ void iscsit_dec_session_usage_count(struct iscsit_session *sess) spin_lock_bh(&sess->session_usage_lock); sess->session_usage_count--; - if (!sess->session_usage_count && sess->session_waiting_on_uc) + if (!sess->session_usage_count && sess->session_waiting_on_uc) { + spin_unlock_bh(&sess->session_usage_lock); complete(&sess->session_waiting_on_uc_comp); + return; + } spin_unlock_bh(&sess->session_usage_lock); } From 7fe6806a7f127156fcb9045d1b75a272cae1154b Mon Sep 17 00:00:00 2001 From: Roxana Nicolescu Date: Thu, 23 Apr 2026 15:51:08 +0200 Subject: [PATCH 4/6] net: add skb_header_pointer_careful() helper jira VULN-176130 cve-pre CVE-2026-23204 commit-author Eric Dumazet commit 13e00fdc9236bd4d0bff4109d2983171fbcb74c4 upstream-diff | Adjusted context because skb_pointer_if_linear does not exist. Introduced in 6f5a630d7c57c ("bpf, net: Introduce skb_pointer_if_linear().") This variant of skb_header_pointer() should be used in contexts where @offset argument is user-controlled and could be negative. Negative offsets are supported, as long as the zone starts between skb->head and skb->data. Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260128141539.3404400-2-edumazet@google.com Signed-off-by: Jakub Kicinski (cherry picked from commit 13e00fdc9236bd4d0bff4109d2983171fbcb74c4) Signed-off-by: Roxana Nicolescu --- include/linux/skbuff.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 5c0f203546dd1..a229b92eae699 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3933,6 +3933,18 @@ skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer) skb_headlen(skb), buffer); } +/* Variant of skb_header_pointer() where @offset is user-controlled + * and potentially negative. + */ +static inline void * __must_check +skb_header_pointer_careful(const struct sk_buff *skb, int offset, + int len, void *buffer) +{ + if (unlikely(offset < 0 && -offset > skb_headroom(skb))) + return NULL; + return skb_header_pointer(skb, offset, len, buffer); +} + /** * skb_needs_linearize - check if we need to linearize a given skb * depending on the given device features. From cb06731b12e405a0ae83989e8a6dc3ba2f0cd56f Mon Sep 17 00:00:00 2001 From: CIQ Kernel Automation Date: Thu, 30 Apr 2026 07:10:09 +0000 Subject: [PATCH 5/6] net/sched: cls_u32: use skb_header_pointer_careful() jira VULN-176130 cve CVE-2026-23204 commit-author Eric Dumazet commit cabd1a976375780dabab888784e356f574bbaed8 skb_header_pointer() does not fully validate negative @offset values. Use skb_header_pointer_careful() instead. GangMin Kim provided a report and a repro fooling u32_classify(): BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0 net/sched/cls_u32.c:221 Fixes: fbc2e7d9cf49 ("cls_u32: use skb_header_pointer() to dereference data safely") Reported-by: GangMin Kim Closes: https://lore.kernel.org/netdev/CANn89iJkyUZ=mAzLzC4GdcAgLuPnUoivdLaOs6B9rq5_erj76w@mail.gmail.com/T/ Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260128141539.3404400-3-edumazet@google.com Signed-off-by: Jakub Kicinski (cherry picked from commit cabd1a976375780dabab888784e356f574bbaed8) Signed-off-by: CIQ Kernel Automation --- net/sched/cls_u32.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index da4c179a4d418..40e7efabe2358 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -151,10 +151,8 @@ TC_INDIRECT_SCOPE int u32_classify(struct sk_buff *skb, int toff = off + key->off + (off2 & key->offmask); __be32 *data, hdata; - if (skb_headroom(skb) + toff > INT_MAX) - goto out; - - data = skb_header_pointer(skb, toff, 4, &hdata); + data = skb_header_pointer_careful(skb, toff, 4, + &hdata); if (!data) goto out; if ((*data ^ key->val) & key->mask) { @@ -204,8 +202,9 @@ TC_INDIRECT_SCOPE int u32_classify(struct sk_buff *skb, if (ht->divisor) { __be32 *data, hdata; - data = skb_header_pointer(skb, off + n->sel.hoff, 4, - &hdata); + data = skb_header_pointer_careful(skb, + off + n->sel.hoff, + 4, &hdata); if (!data) goto out; sel = ht->divisor & u32_hash_fold(*data, &n->sel, @@ -219,7 +218,7 @@ TC_INDIRECT_SCOPE int u32_classify(struct sk_buff *skb, if (n->sel.flags & TC_U32_VAROFFSET) { __be16 *data, hdata; - data = skb_header_pointer(skb, + data = skb_header_pointer_careful(skb, off + n->sel.offoff, 2, &hdata); if (!data) From ff311956de351936d31f3b7ab6a712d8d62efa76 Mon Sep 17 00:00:00 2001 From: CIQ Kernel Automation Date: Thu, 30 Apr 2026 07:10:48 +0000 Subject: [PATCH 6/6] netfilter: nf_tables: fix inverted genmask check in nft_map_catchall_activate() jira VULN-176073 cve CVE-2026-23111 commit-author Andrew Fasano commit f41c5d151078c5348271ffaf8e7410d96f2d82f8 nft_map_catchall_activate() has an inverted element activity check compared to its non-catchall counterpart nft_mapelem_activate() and compared to what is logically required. nft_map_catchall_activate() is called from the abort path to re-activate catchall map elements that were deactivated during a failed transaction. It should skip elements that are already active (they don't need re-activation) and process elements that are inactive (they need to be restored). Instead, the current code does the opposite: it skips inactive elements and processes active ones. Compare the non-catchall activate callback, which is correct: nft_mapelem_activate(): if (nft_set_elem_active(ext, iter->genmask)) return 0; /* skip active, process inactive */ With the buggy catchall version: nft_map_catchall_activate(): if (!nft_set_elem_active(ext, genmask)) continue; /* skip inactive, process active */ The consequence is that when a DELSET operation is aborted, nft_setelem_data_activate() is never called for the catchall element. For NFT_GOTO verdict elements, this means nft_data_hold() is never called to restore the chain->use reference count. Each abort cycle permanently decrements chain->use. Once chain->use reaches zero, DELCHAIN succeeds and frees the chain while catchall verdict elements still reference it, resulting in a use-after-free. This is exploitable for local privilege escalation from an unprivileged user via user namespaces + nftables on distributions that enable CONFIG_USER_NS and CONFIG_NF_TABLES. Fix by removing the negation so the check matches nft_mapelem_activate(): skip active elements, process inactive ones. Fixes: 628bd3e49cba ("netfilter: nf_tables: drop map element references from preparation phase") Signed-off-by: Andrew Fasano Signed-off-by: Florian Westphal (cherry picked from commit f41c5d151078c5348271ffaf8e7410d96f2d82f8) Signed-off-by: CIQ Kernel Automation --- net/netfilter/nf_tables_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 3747144c56142..75d84c596f10d 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5227,7 +5227,7 @@ static void nft_map_catchall_activate(const struct nft_ctx *ctx, list_for_each_entry(catchall, &set->catchall_list, list) { ext = nft_set_elem_ext(set, catchall->elem); - if (!nft_set_elem_active(ext, genmask)) + if (nft_set_elem_active(ext, genmask)) continue; elem.priv = catchall->elem;