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[PATCH openEuler-22.03-LTS-SP1 0/2] CVE-2022-48966
by Zeng Heng 04 Nov '24

04 Nov '24

Dan Carpenter (2): net: mvneta: Prevent out of bounds read in mvneta_config_rss() net: mvneta: Fix an out of bounds check drivers/net/ethernet/marvell/mvneta.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.25.1

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[PATCH OLK-6.6] mm/mremap: fix move_normal_pmd/retract_page_tables race
by Kaixiong Yu 04 Nov '24

04 Nov '24

From: Jann Horn <jannh(a)google.com> stable inclusion from stable-v6.6.58 commit 17396e32f975130b3e6251f024c8807d192e4c3e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAZ7TE CVE: CVE-2024-50066 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 6fa1066fc5d00cb9f1b0e83b7ff6ef98d26ba2aa upstream. In mremap(), move_page_tables() looks at the type of the PMD entry and the specified address range to figure out by which method the next chunk of page table entries should be moved. At that point, the mmap_lock is held in write mode, but no rmap locks are held yet. For PMD entries that point to page tables and are fully covered by the source address range, move_pgt_entry(NORMAL_PMD, ...) is called, which first takes rmap locks, then does move_normal_pmd(). move_normal_pmd() takes the necessary page table locks at source and destination, then moves an entire page table from the source to the destination. The problem is: The rmap locks, which protect against concurrent page table removal by retract_page_tables() in the THP code, are only taken after the PMD entry has been read and it has been decided how to move it. So we can race as follows (with two processes that have mappings of the same tmpfs file that is stored on a tmpfs mount with huge=advise); note that process A accesses page tables through the MM while process B does it through the file rmap: process A process B ========= ========= mremap mremap_to move_vma move_page_tables get_old_pmd alloc_new_pmd *** PREEMPT *** madvise(MADV_COLLAPSE) do_madvise madvise_walk_vmas madvise_vma_behavior madvise_collapse hpage_collapse_scan_file collapse_file retract_page_tables i_mmap_lock_read(mapping) pmdp_collapse_flush i_mmap_unlock_read(mapping) move_pgt_entry(NORMAL_PMD, ...) take_rmap_locks move_normal_pmd drop_rmap_locks When this happens, move_normal_pmd() can end up creating bogus PMD entries in the line `pmd_populate(mm, new_pmd, pmd_pgtable(pmd))`. The effect depends on arch-specific and machine-specific details; on x86, you can end up with physical page 0 mapped as a page table, which is likely exploitable for user->kernel privilege escalation. Fix the race by letting process B recheck that the PMD still points to a page table after the rmap locks have been taken. Otherwise, we bail and let the caller fall back to the PTE-level copying path, which will then bail immediately at the pmd_none() check. Bug reachability: Reaching this bug requires that you can create shmem/file THP mappings - anonymous THP uses different code that doesn't zap stuff under rmap locks. File THP is gated on an experimental config flag (CONFIG_READ_ONLY_THP_FOR_FS), so on normal distro kernels you need shmem THP to hit this bug. As far as I know, getting shmem THP normally requires that you can mount your own tmpfs with the right mount flags, which would require creating your own user+mount namespace; though I don't know if some distros maybe enable shmem THP by default or something like that. Bug impact: This issue can likely be used for user->kernel privilege escalation when it is reachable. Link: https://lkml.kernel.org/r/20241007-move_normal_pmd-vs-collapse-fix-2-v1-1-5… Fixes: 1d65b771bc08 ("mm/khugepaged: retract_page_tables() without mmap or vma lock") Signed-off-by: Jann Horn <jannh(a)google.com> Signed-off-by: David Hildenbrand <david(a)redhat.com> Co-developed-by: David Hildenbrand <david(a)redhat.com> Closes: https://project-zero.issues.chromium.org/371047675 Acked-by: Qi Zheng <zhengqi.arch(a)bytedance.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Hugh Dickins <hughd(a)google.com> Cc: Joel Fernandes <joel(a)joelfernandes.org> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Kaixiong Yu <yukaixiong(a)huawei.com> --- mm/mremap.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index 5d701d3c4f6b..e990bb8c8918 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -240,6 +240,7 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, { spinlock_t *old_ptl, *new_ptl; struct mm_struct *mm = vma->vm_mm; + bool res = false; pmd_t pmd; if (!arch_supports_page_table_move()) @@ -279,19 +280,25 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, if (new_ptl != old_ptl) spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); - /* Clear the pmd */ pmd = *old_pmd; + + /* Racing with collapse? */ + if (unlikely(!pmd_present(pmd) || pmd_leaf(pmd))) + goto out_unlock; + /* Clear the pmd */ pmd_clear(old_pmd); + res = true; VM_BUG_ON(!pmd_none(*new_pmd)); pmd_populate(mm, new_pmd, pmd_pgtable(pmd)); flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE); +out_unlock: if (new_ptl != old_ptl) spin_unlock(new_ptl); spin_unlock(old_ptl); - return true; + return res; } #else static inline bool move_normal_pmd(struct vm_area_struct *vma, -- 2.34.1

2 1

[PATCH openEuler-1.0-LTS] net: fix crash when config small gso_max_size/gso_ipv4_max_size
by Wang Liang 04 Nov '24

04 Nov '24

mainline inclusion from mainline-v6.12-rc6 commit 9ab5cf19fb0e4680f95e506d6c544259bf1111c4 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAY2B4 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- Config a small gso_max_size/gso_ipv4_max_size will lead to an underflow in sk_dst_gso_max_size(), which may trigger a BUG_ON crash, because sk->sk_gso_max_size would be much bigger than device limits. Call Trace: tcp_write_xmit tso_segs = tcp_init_tso_segs(skb, mss_now); tcp_set_skb_tso_segs tcp_skb_pcount_set // skb->len = 524288, mss_now = 8 // u16 tso_segs = 524288/8 = 65535 -> 0 tso_segs = DIV_ROUND_UP(skb->len, mss_now) BUG_ON(!tso_segs) Add check for the minimum value of gso_max_size and gso_ipv4_max_size. Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation") Conflicts: net/core/rtnetlink.c [conflicts due to not mergered 3e48be05f3c7 ("netlink: add attribute range validation to policy"), conflicts due to not mergered 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device")] Signed-off-by: Wang Liang <wangliang74(a)huawei.com> Reviewed-by: Eric Dumazet <edumazet(a)google.com> Link: https://patch.msgid.link/20241023035213.517386-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> --- net/core/rtnetlink.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9209623ab644..c66f60941e5b 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2072,6 +2072,11 @@ static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[]) if (tb[IFLA_BROADCAST] && nla_len(tb[IFLA_BROADCAST]) < dev->addr_len) return -EINVAL; + + if (tb[IFLA_GSO_MAX_SIZE] && + (nla_get_u32(tb[IFLA_GSO_MAX_SIZE]) < MAX_TCP_HEADER + 1)) { + return -EINVAL; + } } if (tb[IFLA_AF_SPEC]) { -- 2.34.1

2 1

[PATCH OLK-5.10] net: mvneta: Prevent out of bounds read in mvneta_config_rss()
by Zeng Heng 04 Nov '24

04 Nov '24

From: Dan Carpenter <error27(a)gmail.com> stable inclusion from stable-v5.10.159 commit 146ebee8fcdb349d7ec0e49915e6cdafb92544ae category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7NTXH Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit e8b4fc13900b8e8be48debffd0dfd391772501f7 ] The pp->indir[0] value comes from the user. It is passed to: if (cpu_online(pp->rxq_def)) inside the mvneta_percpu_elect() function. It needs bounds checkeding to ensure that it is not beyond the end of the cpu bitmap. Fixes: cad5d847a093 ("net: mvneta: Fix the CPU choice in mvneta_percpu_elect") Signed-off-by: Dan Carpenter <error27(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/net/ethernet/marvell/mvneta.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 10a53303de85..7deffbcad6b6 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -4778,6 +4778,9 @@ static int mvneta_config_rss(struct mvneta_port *pp) napi_disable(&pp->napi); } + if (pp->indir[0] >= nr_cpu_ids) + return -EINVAL; + pp->rxq_def = pp->indir[0]; /* Update unicast mapping */ -- 2.25.1

2 1

[openeuler:OLK-5.10 2284/2284] include/linux/compiler_attributes.h:221:41: warning: attribute 'fallthrough' not preceding a case label or default label
by kernel test robot 04 Nov '24

04 Nov '24

tree: https://gitee.com/openeuler/kernel.git OLK-5.10 head: f57c7b292bcdd58fd6816e9636768ef58adf9ff7 commit: 06fcc73ce3f691a693a5bfbca2ba3b490bd25b65 [2284/2284] driver/arm/spe: making mem_sampling and perf mutually exclusive with spe driver config: arm64-randconfig-003-20241029 (https://download.01.org/0day-ci/archive/20241104/202411041220.EBEmz3cz-lkp@…) compiler: aarch64-linux-gcc (GCC) 14.1.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241104/202411041220.EBEmz3cz-lkp@…) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp(a)intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202411041220.EBEmz3cz-lkp@intel.com/ All warnings (new ones prefixed by >>): In file included from include/linux/compiler_types.h:65, from <command-line>: drivers/arm/spe/spe.c: In function '__arm_spe_dev_probe': >> include/linux/compiler_attributes.h:221:41: warning: attribute 'fallthrough' not preceding a case label or default label 221 | # define fallthrough __attribute__((__fallthrough__)) | ^~~~~~~~~~~~~ drivers/arm/spe/spe.c:492:17: note: in expansion of macro 'fallthrough' 492 | fallthrough; | ^~~~~~~~~~~ >> include/linux/compiler_attributes.h:221:41: warning: attribute 'fallthrough' not preceding a case label or default label 221 | # define fallthrough __attribute__((__fallthrough__)) | ^~~~~~~~~~~~~ drivers/arm/spe/spe.c:514:17: note: in expansion of macro 'fallthrough' 514 | fallthrough; | ^~~~~~~~~~~ vim +/fallthrough +221 include/linux/compiler_attributes.h 294f69e662d157 Joe Perches 2019-10-05 209 294f69e662d157 Joe Perches 2019-10-05 210 /* 294f69e662d157 Joe Perches 2019-10-05 211 * Add the pseudo keyword 'fallthrough' so case statement blocks 294f69e662d157 Joe Perches 2019-10-05 212 * must end with any of these keywords: 294f69e662d157 Joe Perches 2019-10-05 213 * break; 294f69e662d157 Joe Perches 2019-10-05 214 * fallthrough; 294f69e662d157 Joe Perches 2019-10-05 215 * goto <label>; 294f69e662d157 Joe Perches 2019-10-05 216 * return [expression]; 294f69e662d157 Joe Perches 2019-10-05 217 * 294f69e662d157 Joe Perches 2019-10-05 218 * gcc: https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html#Statement-Attr… 294f69e662d157 Joe Perches 2019-10-05 219 */ 294f69e662d157 Joe Perches 2019-10-05 220 #if __has_attribute(__fallthrough__) 294f69e662d157 Joe Perches 2019-10-05 @221 # define fallthrough __attribute__((__fallthrough__)) 294f69e662d157 Joe Perches 2019-10-05 222 #else 294f69e662d157 Joe Perches 2019-10-05 223 # define fallthrough do {} while (0) /* fallthrough */ a3f8a30f3f0079 Miguel Ojeda 2018-08-30 224 #endif a3f8a30f3f0079 Miguel Ojeda 2018-08-30 225 :::::: The code at line 221 was first introduced by commit :::::: 294f69e662d1570703e9b56e95be37a9fd3afba5 compiler_attributes.h: Add 'fallthrough' pseudo keyword for switch/case use :::::: TO: Joe Perches <joe(a)perches.com> :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki

1 0

[PATCH OLK-6.6 0/2] CVE-2024-49968
by Yongjian Sun 04 Nov '24

04 Nov '24

*** BLURB HERE *** Gabriel Krisman Bertazi (1): [Backport] ext4: fix error message when rejecting the default hash Lizhi Xu (1): [Backport] ext4: filesystems without casefold feature cannot be mounted with siphash fs/ext4/ext4.h | 1 + fs/ext4/super.c | 20 +++++++++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-) -- 2.39.2

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[PATCH OLK-6.6] [Backport] exfat: fix memory leak in exfat_load_bitmap()
by Yongjian Sun 04 Nov '24

04 Nov '24

From: Yuezhang Mo <Yuezhang.Mo(a)sony.com> mainline inclusion from mainline-v6.12-rc1 commit d2b537b3e533f28e0d97293fe9293161fe8cd137 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRBG CVE: CVE-2024-50013 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- If the first directory entry in the root directory is not a bitmap directory entry, 'bh' will not be released and reassigned, which will cause a memory leak. Fixes: 1e49a94cf707 ("exfat: add bitmap operations") Cc: stable(a)vger.kernel.org Signed-off-by: Yuezhang Mo <Yuezhang.Mo(a)sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama(a)sony.com> Signed-off-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Yongjian Sun <sunyongjian1(a)huawei.com> --- fs/exfat/balloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index e918decb3735..5b547a596380 100644 --- a/fs/exfat/balloc.c +++ b/fs/exfat/balloc.c @@ -110,11 +110,8 @@ int exfat_load_bitmap(struct super_block *sb) return -EIO; type = exfat_get_entry_type(ep); - if (type == TYPE_UNUSED) - break; - if (type != TYPE_BITMAP) - continue; - if (ep->dentry.bitmap.flags == 0x0) { + if (type == TYPE_BITMAP && + ep->dentry.bitmap.flags == 0x0) { int err; err = exfat_allocate_bitmap(sb, ep); @@ -122,6 +119,9 @@ int exfat_load_bitmap(struct super_block *sb) return err; } brelse(bh); + + if (type == TYPE_UNUSED) + return -EINVAL; } if (exfat_get_next_cluster(sb, &clu.dir)) -- 2.39.2

2 11

[PATCH OLK-5.10] [Backport] exfat: fix memory leak in exfat_load_bitmap()
by Yongjian Sun 04 Nov '24

04 Nov '24

From: Yuezhang Mo <Yuezhang.Mo(a)sony.com> mainline inclusion from mainline-v6.12-rc1 commit d2b537b3e533f28e0d97293fe9293161fe8cd137 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRBG CVE: CVE-2024-50013 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- If the first directory entry in the root directory is not a bitmap directory entry, 'bh' will not be released and reassigned, which will cause a memory leak. Fixes: 1e49a94cf707 ("exfat: add bitmap operations") Cc: stable(a)vger.kernel.org Signed-off-by: Yuezhang Mo <Yuezhang.Mo(a)sony.com> Reviewed-by: Aoyama Wataru <wataru.aoyama(a)sony.com> Signed-off-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Yongjian Sun <sunyongjian1(a)huawei.com> --- fs/exfat/balloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index ab091440e8b9..0501b8c04d8d 100644 --- a/fs/exfat/balloc.c +++ b/fs/exfat/balloc.c @@ -110,11 +110,8 @@ int exfat_load_bitmap(struct super_block *sb) return -EIO; type = exfat_get_entry_type(ep); - if (type == TYPE_UNUSED) - break; - if (type != TYPE_BITMAP) - continue; - if (ep->dentry.bitmap.flags == 0x0) { + if (type == TYPE_BITMAP && + ep->dentry.bitmap.flags == 0x0) { int err; err = exfat_allocate_bitmap(sb, ep); @@ -122,6 +119,9 @@ int exfat_load_bitmap(struct super_block *sb) return err; } brelse(bh); + + if (type == TYPE_UNUSED) + return -EINVAL; } if (exfat_get_next_cluster(sb, &clu.dir)) -- 2.39.2

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[PATCH OLK-6.6] bpf: Fail verification for sign-extension of packet data/data_end/data_meta
by Chen Zhongjin 04 Nov '24

04 Nov '24

From: Yonghong Song <yonghong.song(a)linux.dev> mainline inclusion from mainline-v6.12-rc1 commit 92de36080c93296ef9005690705cba260b9bd68a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYPJQ CVE: CVE-2024-47702 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- syzbot reported a kernel crash due to commit 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses"). The reason is due to sign-extension of 32-bit load for packet data/data_end/data_meta uapi field. The original code looks like: r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */ r0 = r2 r0 += 8 if r3 > r0 goto +1 ... Note that __sk_buff->data load has 32-bit sign extension. After verification and convert_ctx_accesses(), the final asm code looks like: r2 = *(u64 *)(r1 +208) r2 = (s32)r2 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 ... Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid which may cause runtime failure. Currently, in C code, typically we have void *data = (void *)(long)skb->data; void *data_end = (void *)(long)skb->data_end; ... and it will generate r2 = *(u64 *)(r1 +208) r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 If we allow sign-extension, void *data = (void *)(long)(int)skb->data; void *data_end = (void *)(long)skb->data_end; ... the generated code looks like r2 = *(u64 *)(r1 +208) r2 <<= 32 r2 s>>= 32 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 and this will cause verification failure since "r2 <<= 32" is not allowed as "r2" is a packet pointer. To fix this issue for case r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ this patch added additional checking in is_valid_access() callback function for packet data/data_end/data_meta access. If those accesses are with sign-extenstion, the verification will fail. [1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/ Reported-by: syzbot+ad9ec60c8eaf69e6f99c(a)syzkaller.appspotmail.com Fixes: 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses") Acked-by: Eduard Zingerman <eddyz87(a)gmail.com> Signed-off-by: Yonghong Song <yonghong.song(a)linux.dev> Link: https://lore.kernel.org/r/20240723153439.2429035-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Conflicts: kernel/bpf/verifier.c [patch set:("bpf, lsm: Add check for BPF LSM return value") was not merged] include/linux/bpf.h [fix struct bpf_insn_access_aux KABI breakage] Signed-off-by: Chen Zhongjin <chenzhongjin(a)huawei.com> --- include/linux/bpf.h | 1 + kernel/bpf/verifier.c | 5 +++-- net/core/filter.c | 21 ++++++++++++++++----- 3 files changed, 20 insertions(+), 7 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8c4c2c39a6c1..c9351ab31e05 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -920,6 +920,7 @@ struct bpf_insn_access_aux { }; }; struct bpf_verifier_log *log; /* for verbose logs */ + KABI_EXTEND(bool is_ldsx) }; static inline void diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d1041517a984..82f2be2ddd06 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5549,11 +5549,12 @@ static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off, /* check access to 'struct bpf_context' fields. Supports fixed offsets only */ static int check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int off, int size, enum bpf_access_type t, enum bpf_reg_type *reg_type, - struct btf **btf, u32 *btf_id) + struct btf **btf, u32 *btf_id, bool is_ldsx) { struct bpf_insn_access_aux info = { .reg_type = *reg_type, .log = &env->log, + .is_ldsx = is_ldsx, }; if (env->ops->is_valid_access && @@ -6802,7 +6803,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn return err; err = check_ctx_access(env, insn_idx, off, size, t, &reg_type, &btf, - &btf_id); + &btf_id, is_ldsx); if (err) verbose_linfo(env, insn_idx, "; "); if (!err && t == BPF_READ && value_regno >= 0) { diff --git a/net/core/filter.c b/net/core/filter.c index e16d746c23da..e4f1dc9f222b 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -8601,13 +8601,16 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type if (off + size > offsetofend(struct __sk_buff, cb[4])) return false; break; + case bpf_ctx_range(struct __sk_buff, data): + case bpf_ctx_range(struct __sk_buff, data_meta): + case bpf_ctx_range(struct __sk_buff, data_end): + if (info->is_ldsx || size != size_default) + return false; + break; case bpf_ctx_range_till(struct __sk_buff, remote_ip6[0], remote_ip6[3]): case bpf_ctx_range_till(struct __sk_buff, local_ip6[0], local_ip6[3]): case bpf_ctx_range_till(struct __sk_buff, remote_ip4, remote_ip4): case bpf_ctx_range_till(struct __sk_buff, local_ip4, local_ip4): - case bpf_ctx_range(struct __sk_buff, data): - case bpf_ctx_range(struct __sk_buff, data_meta): - case bpf_ctx_range(struct __sk_buff, data_end): if (size != size_default) return false; break; @@ -9051,6 +9054,14 @@ static bool xdp_is_valid_access(int off, int size, } } return false; + } else { + switch (off) { + case offsetof(struct xdp_md, data_meta): + case offsetof(struct xdp_md, data): + case offsetof(struct xdp_md, data_end): + if (info->is_ldsx) + return false; + } } switch (off) { @@ -9381,12 +9392,12 @@ static bool flow_dissector_is_valid_access(int off, int size, switch (off) { case bpf_ctx_range(struct __sk_buff, data): - if (size != size_default) + if (info->is_ldsx || size != size_default) return false; info->reg_type = PTR_TO_PACKET; return true; case bpf_ctx_range(struct __sk_buff, data_end): - if (size != size_default) + if (info->is_ldsx || size != size_default) return false; info->reg_type = PTR_TO_PACKET_END; return true; -- 2.25.1

2 1

[PATCH OLK-6.6 v2] bpf: Fail verification for sign-extension of packet data/data_end/data_meta
by Chen Zhongjin 04 Nov '24

04 Nov '24

From: Yonghong Song <yonghong.song(a)linux.dev> mainline inclusion from mainline-v6.12-rc1 commit 92de36080c93296ef9005690705cba260b9bd68a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYPJQ CVE: CVE-2024-47702 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- syzbot reported a kernel crash due to commit 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses"). The reason is due to sign-extension of 32-bit load for packet data/data_end/data_meta uapi field. The original code looks like: r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */ r0 = r2 r0 += 8 if r3 > r0 goto +1 ... Note that __sk_buff->data load has 32-bit sign extension. After verification and convert_ctx_accesses(), the final asm code looks like: r2 = *(u64 *)(r1 +208) r2 = (s32)r2 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 ... Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid which may cause runtime failure. Currently, in C code, typically we have void *data = (void *)(long)skb->data; void *data_end = (void *)(long)skb->data_end; ... and it will generate r2 = *(u64 *)(r1 +208) r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 If we allow sign-extension, void *data = (void *)(long)(int)skb->data; void *data_end = (void *)(long)skb->data_end; ... the generated code looks like r2 = *(u64 *)(r1 +208) r2 <<= 32 r2 s>>= 32 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 and this will cause verification failure since "r2 <<= 32" is not allowed as "r2" is a packet pointer. To fix this issue for case r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ this patch added additional checking in is_valid_access() callback function for packet data/data_end/data_meta access. If those accesses are with sign-extenstion, the verification will fail. [1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/ Reported-by: syzbot+ad9ec60c8eaf69e6f99c(a)syzkaller.appspotmail.com Fixes: 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses") Acked-by: Eduard Zingerman <eddyz87(a)gmail.com> Signed-off-by: Yonghong Song <yonghong.song(a)linux.dev> Link: https://lore.kernel.org/r/20240723153439.2429035-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Andrii Nakryiko <andrii(a)kernel.org> Conflicts: kernel/bpf/verifier.c [patch set:("bpf, lsm: Add check for BPF LSM return value") was not merged] include/linux/bpf.h [fix struct bpf_insn_access_aux KABI breakage] Signed-off-by: Chen Zhongjin <chenzhongjin(a)huawei.com> --- include/linux/bpf.h | 1 + kernel/bpf/verifier.c | 5 +++-- net/core/filter.c | 21 ++++++++++++++++----- 3 files changed, 20 insertions(+), 7 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8c4c2c39a6c1..c9351ab31e05 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -920,6 +920,7 @@ struct bpf_insn_access_aux { }; }; struct bpf_verifier_log *log; /* for verbose logs */ + KABI_EXTEND(bool is_ldsx) }; static inline void diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d1041517a984..82f2be2ddd06 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5549,11 +5549,12 @@ static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off, /* check access to 'struct bpf_context' fields. Supports fixed offsets only */ static int check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int off, int size, enum bpf_access_type t, enum bpf_reg_type *reg_type, - struct btf **btf, u32 *btf_id) + struct btf **btf, u32 *btf_id, bool is_ldsx) { struct bpf_insn_access_aux info = { .reg_type = *reg_type, .log = &env->log, + .is_ldsx = is_ldsx, }; if (env->ops->is_valid_access && @@ -6802,7 +6803,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn return err; err = check_ctx_access(env, insn_idx, off, size, t, &reg_type, &btf, - &btf_id); + &btf_id, is_ldsx); if (err) verbose_linfo(env, insn_idx, "; "); if (!err && t == BPF_READ && value_regno >= 0) { diff --git a/net/core/filter.c b/net/core/filter.c index e16d746c23da..e4f1dc9f222b 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -8601,13 +8601,16 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type if (off + size > offsetofend(struct __sk_buff, cb[4])) return false; break; + case bpf_ctx_range(struct __sk_buff, data): + case bpf_ctx_range(struct __sk_buff, data_meta): + case bpf_ctx_range(struct __sk_buff, data_end): + if (info->is_ldsx || size != size_default) + return false; + break; case bpf_ctx_range_till(struct __sk_buff, remote_ip6[0], remote_ip6[3]): case bpf_ctx_range_till(struct __sk_buff, local_ip6[0], local_ip6[3]): case bpf_ctx_range_till(struct __sk_buff, remote_ip4, remote_ip4): case bpf_ctx_range_till(struct __sk_buff, local_ip4, local_ip4): - case bpf_ctx_range(struct __sk_buff, data): - case bpf_ctx_range(struct __sk_buff, data_meta): - case bpf_ctx_range(struct __sk_buff, data_end): if (size != size_default) return false; break; @@ -9051,6 +9054,14 @@ static bool xdp_is_valid_access(int off, int size, } } return false; + } else { + switch (off) { + case offsetof(struct xdp_md, data_meta): + case offsetof(struct xdp_md, data): + case offsetof(struct xdp_md, data_end): + if (info->is_ldsx) + return false; + } } switch (off) { @@ -9381,12 +9392,12 @@ static bool flow_dissector_is_valid_access(int off, int size, switch (off) { case bpf_ctx_range(struct __sk_buff, data): - if (size != size_default) + if (info->is_ldsx || size != size_default) return false; info->reg_type = PTR_TO_PACKET; return true; case bpf_ctx_range(struct __sk_buff, data_end): - if (size != size_default) + if (info->is_ldsx || size != size_default) return false; info->reg_type = PTR_TO_PACKET_END; return true; -- 2.25.1

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