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[PATCH OLK-5.10] tracing: Take trace_array reference when opening options file
by Tengda Wu 18 Sep '26

18 Sep '26

From: Steven Rostedt <rostedt(a)goodmis.org> mainline inclusion from mainline-v7.3-rc2 commit f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19114 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The options files do not take the trace_array reference for the options they represent. This could cause a use-after-free kernel crash if one of these files is opened by one task and another task removes the instance that the option is for. Because it doesn't take a reference upon opening, it will not stop the removal which will free the options descriptor that is being used. As the options are somewhat dynamic in their creation at boot up, each file represents a flag in the trace_array. The trace_array has an array of indexes to represent each of these flags that is stored in the trace_flags_index array. The address of the index array element is used to pass to the inode->i_private pointer. Then that element is read which holds the index (which represents the flag) and then the index is used to calculate the trace_array descriptor from its trace_flags_index array. One issue is that the index element can not be referenced until the trace_array's reference is taken. To handle this, create a new helper function called: trace_array_options_get() that will iterate all the existing trace_arrays in the ftrace_trace_arrays list (under the trace_types_lock), and compare the passed in address of the index element with the entire array of the trace_array's trace_flags_index array. If it matches, then up the corresponding trace_array's reference and return. Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20260902121918.5a9e9d1b@gandalf.local.home Fixes: 577b785f55168 ("tracing: add tracer dependent options to options directory") Reported-by: sashiko-bot(a)kernel.org Closes: https://lore.kernel.org/linux-trace-kernel/20260828135858.2AC501F000E9@smtp… Signed-off-by: Steven Rostedt <rostedt(a)goodmis.org> Conflicts: kernel/trace/trace.c [This version lacks the lock-free __trace_array_get, which is hidden inside a refactoring patch in the mainline, commit eca33fdab47b. To avoid introducing that refactoring patch, __trace_array_get was manually adapted.] Signed-off-by: Tengda Wu <wutengda2(a)huawei.com> --- kernel/trace/trace.c | 79 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 73 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8c4e4cfa2945..7a57721c1a54 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -433,6 +433,12 @@ static struct trace_array global_trace = { LIST_HEAD(ftrace_trace_arrays); +static int __trace_array_get(struct trace_array *this_tr) +{ + this_tr->ref++; + return 0; +} + int trace_array_get(struct trace_array *this_tr) { struct trace_array *tr; @@ -441,8 +447,7 @@ int trace_array_get(struct trace_array *this_tr) mutex_lock(&trace_types_lock); list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (tr == this_tr) { - tr->ref++; - ret = 0; + ret = __trace_array_get(tr); break; } } @@ -8538,11 +8543,73 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, return cnt; } +/* + * The tr_index is the address of a trace_array->trace_flags_index[] + * element that holds the index of the trace flag. But since the + * trace_array reference has not been taken yet, it cannot be referenced + * as it could have been freed by a rmdir of the instance the trace_array + * represents. + * + * Search the list of trace_arrays and compare the tr_index to the + * address of the entire trace_array trace_flags_index array for each + * trace_array in the list. If one is matched, then take the reference + * and return it. If not, the trace_array no longer exits. + */ +static int trace_array_options_get(void *tr_index) +{ + struct trace_array *tr; + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + + if (tracing_disabled) + return -ENODEV; + + mutex_lock(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr_index >= (void *)&tr->trace_flags_index[0] && + tr_index < (void *)&tr->trace_flags_index[TRACE_FLAGS_MAX_SIZE]) { + mutex_unlock(&trace_types_lock); + return __trace_array_get(tr); + } + } + mutex_unlock(&trace_types_lock); + return -ENODEV; +} + +static int trace_options_open(struct inode *inode, struct file *filp) +{ + void *tr_index = inode->i_private; + + if (trace_array_options_get(tr_index) < 0) + return -ENODEV; + + filp->private_data = tr_index; + + return 0; +} + +static int trace_options_release(struct inode *inode, struct file *filp) +{ + void *tr_index = filp->private_data; + struct trace_array *tr; + unsigned int index; + + get_tr_index(tr_index, &tr, &index); + + trace_array_put(tr); + + return 0; +} + static const struct file_operations trace_options_core_fops = { - .open = tracing_open_generic, - .read = trace_options_core_read, - .write = trace_options_core_write, - .llseek = generic_file_llseek, + .open = trace_options_open, + .read = trace_options_core_read, + .write = trace_options_core_write, + .llseek = generic_file_llseek, + .release = trace_options_release, }; struct dentry *trace_create_file(const char *name, -- 2.34.1

2 1

[PATCH OLK-6.6] tracing: Take trace_array reference when opening options file
by Tengda Wu 18 Sep '26

18 Sep '26

From: Steven Rostedt <rostedt(a)goodmis.org> mainline inclusion from mainline-v7.3-rc2 commit f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19114 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The options files do not take the trace_array reference for the options they represent. This could cause a use-after-free kernel crash if one of these files is opened by one task and another task removes the instance that the option is for. Because it doesn't take a reference upon opening, it will not stop the removal which will free the options descriptor that is being used. As the options are somewhat dynamic in their creation at boot up, each file represents a flag in the trace_array. The trace_array has an array of indexes to represent each of these flags that is stored in the trace_flags_index array. The address of the index array element is used to pass to the inode->i_private pointer. Then that element is read which holds the index (which represents the flag) and then the index is used to calculate the trace_array descriptor from its trace_flags_index array. One issue is that the index element can not be referenced until the trace_array's reference is taken. To handle this, create a new helper function called: trace_array_options_get() that will iterate all the existing trace_arrays in the ftrace_trace_arrays list (under the trace_types_lock), and compare the passed in address of the index element with the entire array of the trace_array's trace_flags_index array. If it matches, then up the corresponding trace_array's reference and return. Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20260902121918.5a9e9d1b@gandalf.local.home Fixes: 577b785f55168 ("tracing: add tracer dependent options to options directory") Reported-by: sashiko-bot(a)kernel.org Closes: https://lore.kernel.org/linux-trace-kernel/20260828135858.2AC501F000E9@smtp… Signed-off-by: Steven Rostedt <rostedt(a)goodmis.org> Conflicts: kernel/trace/trace.c [This version lacks the lock-free __trace_array_get, which is hidden inside a refactoring patch in the mainline, commit eca33fdab47b. To avoid introducing that refactoring patch, __trace_array_get was manually adapted.] Signed-off-by: Tengda Wu <wutengda2(a)huawei.com> --- kernel/trace/trace.c | 76 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 70 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 62d20a0d737b..962705fa7894 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -493,6 +493,12 @@ static struct trace_array global_trace = { LIST_HEAD(ftrace_trace_arrays); +static int __trace_array_get(struct trace_array *this_tr) +{ + this_tr->ref++; + return 0; +} + int trace_array_get(struct trace_array *this_tr) { struct trace_array *tr; @@ -501,8 +507,7 @@ int trace_array_get(struct trace_array *this_tr) mutex_lock(&trace_types_lock); list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (tr == this_tr) { - tr->ref++; - ret = 0; + ret = __trace_array_get(tr); break; } } @@ -9032,11 +9037,70 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, return cnt; } +/* + * The tr_index is the address of a trace_array->trace_flags_index[] + * element that holds the index of the trace flag. But since the + * trace_array reference has not been taken yet, it cannot be referenced + * as it could have been freed by a rmdir of the instance the trace_array + * represents. + * + * Search the list of trace_arrays and compare the tr_index to the + * address of the entire trace_array trace_flags_index array for each + * trace_array in the list. If one is matched, then take the reference + * and return it. If not, the trace_array no longer exits. + */ +static int trace_array_options_get(void *tr_index) +{ + struct trace_array *tr; + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + + if (tracing_disabled) + return -ENODEV; + + guard(mutex)(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr_index >= (void *)&tr->trace_flags_index[0] && + tr_index < (void *)&tr->trace_flags_index[TRACE_FLAGS_MAX_SIZE]) + return __trace_array_get(tr); + } + return -ENODEV; +} + +static int trace_options_open(struct inode *inode, struct file *filp) +{ + void *tr_index = inode->i_private; + + if (trace_array_options_get(tr_index) < 0) + return -ENODEV; + + filp->private_data = tr_index; + + return 0; +} + +static int trace_options_release(struct inode *inode, struct file *filp) +{ + void *tr_index = filp->private_data; + struct trace_array *tr; + unsigned int index; + + get_tr_index(tr_index, &tr, &index); + + trace_array_put(tr); + + return 0; +} + static const struct file_operations trace_options_core_fops = { - .open = tracing_open_generic, - .read = trace_options_core_read, - .write = trace_options_core_write, - .llseek = generic_file_llseek, + .open = trace_options_open, + .read = trace_options_core_read, + .write = trace_options_core_write, + .llseek = generic_file_llseek, + .release = trace_options_release, }; struct dentry *trace_create_file(const char *name, -- 2.34.1

2 1

[PATCH openEuler-1.0-LTS] tracing: Take trace_array reference when opening options file
by Tengda Wu 18 Sep '26

18 Sep '26

From: Steven Rostedt <rostedt(a)goodmis.org> mainline inclusion from mainline-v7.3-rc2 commit f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19114 CVE: CVE-2026-90013 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The options files do not take the trace_array reference for the options they represent. This could cause a use-after-free kernel crash if one of these files is opened by one task and another task removes the instance that the option is for. Because it doesn't take a reference upon opening, it will not stop the removal which will free the options descriptor that is being used. As the options are somewhat dynamic in their creation at boot up, each file represents a flag in the trace_array. The trace_array has an array of indexes to represent each of these flags that is stored in the trace_flags_index array. The address of the index array element is used to pass to the inode->i_private pointer. Then that element is read which holds the index (which represents the flag) and then the index is used to calculate the trace_array descriptor from its trace_flags_index array. One issue is that the index element can not be referenced until the trace_array's reference is taken. To handle this, create a new helper function called: trace_array_options_get() that will iterate all the existing trace_arrays in the ftrace_trace_arrays list (under the trace_types_lock), and compare the passed in address of the index element with the entire array of the trace_array's trace_flags_index array. If it matches, then up the corresponding trace_array's reference and return. Cc: stable(a)vger.kernel.org Link: https://patch.msgid.link/20260902121918.5a9e9d1b@gandalf.local.home Fixes: 577b785f55168 ("tracing: add tracer dependent options to options directory") Reported-by: sashiko-bot(a)kernel.org Closes: https://lore.kernel.org/linux-trace-kernel/20260828135858.2AC501F000E9@smtp… Signed-off-by: Steven Rostedt <rostedt(a)goodmis.org> Conflicts: kernel/trace/trace.c [1. This version lacks the lock-free __trace_array_get, which is hidden inside a refactoring patch in the mainline, commit eca33fdab47b. To avoid introducing that refactoring patch, __trace_array_get was manually adapted. 2. This version has no security_locked_down(LOCKDOWN_TRACEFS) mechanism, so it was removed.] Signed-off-by: Tengda Wu <wutengda2(a)huawei.com> --- kernel/trace/trace.c | 74 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 68 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e85b2e082085..91e69ad1181c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -275,6 +275,12 @@ static struct trace_array global_trace = { LIST_HEAD(ftrace_trace_arrays); +static int __trace_array_get(struct trace_array *this_tr) +{ + this_tr->ref++; + return 0; +} + int trace_array_get(struct trace_array *this_tr) { struct trace_array *tr; @@ -283,8 +289,7 @@ int trace_array_get(struct trace_array *this_tr) mutex_lock(&trace_types_lock); list_for_each_entry(tr, &ftrace_trace_arrays, list) { if (tr == this_tr) { - tr->ref++; - ret = 0; + ret = __trace_array_get(tr); break; } } @@ -7496,11 +7501,68 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, return cnt; } +/* + * The tr_index is the address of a trace_array->trace_flags_index[] + * element that holds the index of the trace flag. But since the + * trace_array reference has not been taken yet, it cannot be referenced + * as it could have been freed by a rmdir of the instance the trace_array + * represents. + * + * Search the list of trace_arrays and compare the tr_index to the + * address of the entire trace_array trace_flags_index array for each + * trace_array in the list. If one is matched, then take the reference + * and return it. If not, the trace_array no longer exits. + */ +static int trace_array_options_get(void *tr_index) +{ + struct trace_array *tr; + + if (tracing_disabled) + return -ENODEV; + + mutex_lock(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr_index >= (void *)&tr->trace_flags_index[0] && + tr_index < (void *)&tr->trace_flags_index[TRACE_FLAGS_MAX_SIZE]) { + mutex_unlock(&trace_types_lock); + return __trace_array_get(tr); + } + } + mutex_unlock(&trace_types_lock); + return -ENODEV; +} + +static int trace_options_open(struct inode *inode, struct file *filp) +{ + void *tr_index = inode->i_private; + + if (trace_array_options_get(tr_index) < 0) + return -ENODEV; + + filp->private_data = tr_index; + + return 0; +} + +static int trace_options_release(struct inode *inode, struct file *filp) +{ + void *tr_index = filp->private_data; + struct trace_array *tr; + unsigned int index; + + get_tr_index(tr_index, &tr, &index); + + trace_array_put(tr); + + return 0; +} + static const struct file_operations trace_options_core_fops = { - .open = tracing_open_generic, - .read = trace_options_core_read, - .write = trace_options_core_write, - .llseek = generic_file_llseek, + .open = trace_options_open, + .read = trace_options_core_read, + .write = trace_options_core_write, + .llseek = generic_file_llseek, + .release = trace_options_release, }; struct dentry *trace_create_file(const char *name, -- 2.34.1

2 1

[PATCH OLK-5.10] smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions
by Zizhi Wo 18 Sep '26

18 Sep '26

From: Jiangshan Yi <yijiangshan(a)kylinos.cn> stable inclusion from stable-v6.18.51 commit b10015807e4c628095d1d1d1c9307efc8cdd9e1b category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18923 CVE: CVE-2026-89638 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit… -------------------------------- [ Upstream commit b8e5dc4f95e5484159b343903f302eb6d783f2e6 ] When a file has the setuid or setgid bit set and is written to, the VFS strips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID together with an ATTR_MODE carrying the already-cleared mode. Both cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped ATTR_MODE in that case: /* skip mode change if it's just for clearing setuid/setgid */ if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) attrs->ia_valid &= ~ATTR_MODE; This is fine for the default mount, where the mode is only emulated via the DOS read-only attribute and cannot represent the setuid/setgid bits anyway. However, with the "cifsacl" or "modefromsid" mount options the mode is stored on the server through an ACL (id_mode_to_cifs_acl()), with the SMB3.1.1 POSIX extensions the mode is sent to the server directly, and with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent via CIFSSMBUnixSetPathInfo(). In all those cases dropping ATTR_MODE means the cleared mode is never pushed to the server, so the setuid/setgid bit survives the write. This is a security issue: on local filesystems the setuid bit is stripped when a file is written, but over these cifs.ko mounts the bit persists on the server, potentially allowing an unexpected privilege escalation on subsequent execution. Fix this in two places: 1. cifs_setattr_nounix(): only take the "skip mode change" shortcut when the mode is emulated via the DOS read-only attribute (i.e. neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are in effect), so that the cleared mode is propagated to the server in the ACL / POSIX cases. 2. cifs_setattr_unix(): this function is only called when Unix extensions are in effect, so the mode is always stored on the server. Remove the shortcut entirely so that the cleared mode is always pushed. Fixes: d32c4f2626ac ("CIFS: ignore mode change if it's just for clearing setuid/setgid bits") Cc: stable(a)vger.kernel.org Signed-off-by: Jiangshan Yi <yijiangshan(a)kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Paulo Alcantara <pc(a)manguebit.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Conflicts: fs/cifs/inode.c fs/smb/client/inode.c [Commit b8e5dc4f95e5 touches fs/smb/client/inode.c, which this tree still has as fs/cifs/inode.c. The new check used the upstream-local sbflags variable, which does not exist here, so use cifs_sb->mnt_cifs_flags instead.] Signed-off-by: Zizhi Wo <wozizhi(a)huawei.com> --- fs/cifs/inode.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 045d77a929df..83974a528024 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -2662,13 +2662,17 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs) rc = cifs_set_file_size(inode, attrs, xid, full_path); if (rc != 0) goto out; } - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) - attrs->ia_valid &= ~ATTR_MODE; + /* + * This function is only called when Unix extensions are in effect, + * so the mode is always sent to and stored on the server. Do not + * skip the mode change when clearing setuid/setgid bits: dropping + * ATTR_MODE here would leave those bits set on the server after a + * write, which is a security issue. + */ args = kmalloc(sizeof(*args), GFP_KERNEL); if (args == NULL) { rc = -ENOMEM; goto out; @@ -2848,12 +2852,28 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs) } } else if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) attrs->ia_valid &= ~(ATTR_UID | ATTR_GID); - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) + /* + * Skip the mode change if it is only being done to clear the + * setuid/setgid bits *and* the mode is emulated via the DOS + * read-only attribute (the default, non-ACL case), which cannot + * represent the setuid/setgid bits anyway. + * + * When the mode is instead stored on the server - i.e. with the + * cifsacl or modefromsid mount options (via an ACL) or with the + * SMB3.1.1 POSIX extensions - the cleared mode must be pushed to + * the server. Dropping ATTR_MODE here would leave the setuid/ + * setgid bit set on the server after a write, which is a security + * issue (the bits are not stripped as they are on local + * filesystems). + */ + if ((attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) && + !((cifs_sb->mnt_cifs_flags & + (CIFS_MOUNT_CIFS_ACL | CIFS_MOUNT_MODE_FROM_SID)) || + cifs_sb_master_tcon(cifs_sb)->posix_extensions)) attrs->ia_valid &= ~ATTR_MODE; if (attrs->ia_valid & ATTR_MODE) { mode = attrs->ia_mode; rc = 0; -- 2.52.0

2 1

[PATCH openEuler-1.0-LTS] smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions
by Zizhi Wo 18 Sep '26

18 Sep '26

From: Jiangshan Yi <yijiangshan(a)kylinos.cn> stable inclusion from stable-v6.18.51 commit b10015807e4c628095d1d1d1c9307efc8cdd9e1b category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18923 CVE: CVE-2026-89638 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit… -------------------------------- [ Upstream commit b8e5dc4f95e5484159b343903f302eb6d783f2e6 ] When a file has the setuid or setgid bit set and is written to, the VFS strips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID together with an ATTR_MODE carrying the already-cleared mode. Both cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped ATTR_MODE in that case: /* skip mode change if it's just for clearing setuid/setgid */ if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) attrs->ia_valid &= ~ATTR_MODE; This is fine for the default mount, where the mode is only emulated via the DOS read-only attribute and cannot represent the setuid/setgid bits anyway. However, with the "cifsacl" or "modefromsid" mount options the mode is stored on the server through an ACL (id_mode_to_cifs_acl()), with the SMB3.1.1 POSIX extensions the mode is sent to the server directly, and with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent via CIFSSMBUnixSetPathInfo(). In all those cases dropping ATTR_MODE means the cleared mode is never pushed to the server, so the setuid/setgid bit survives the write. This is a security issue: on local filesystems the setuid bit is stripped when a file is written, but over these cifs.ko mounts the bit persists on the server, potentially allowing an unexpected privilege escalation on subsequent execution. Fix this in two places: 1. cifs_setattr_nounix(): only take the "skip mode change" shortcut when the mode is emulated via the DOS read-only attribute (i.e. neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are in effect), so that the cleared mode is propagated to the server in the ACL / POSIX cases. 2. cifs_setattr_unix(): this function is only called when Unix extensions are in effect, so the mode is always stored on the server. Remove the shortcut entirely so that the cleared mode is always pushed. Fixes: d32c4f2626ac ("CIFS: ignore mode change if it's just for clearing setuid/setgid bits") Cc: stable(a)vger.kernel.org Signed-off-by: Jiangshan Yi <yijiangshan(a)kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Paulo Alcantara <pc(a)manguebit.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Conflicts: fs/cifs/inode.c fs/smb/client/inode.c [1. Commit b8e5dc4f95e5 touches fs/smb/client/inode.c, which this tree still has as fs/cifs/inode.c. The new check used the upstream-local sbflags variable, which does not exist here, so use cifs_sb->mnt_cifs_flags instead. 2. Commit 412094a8fb07 ("smb3: add new mount option to retrieve mode from special ACE") introduce CIFS_MOUNT_MODE_FROM_SID, this version has not merged.] Signed-off-by: Zizhi Wo <wozizhi(a)huawei.com> --- fs/cifs/inode.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index e5d0066f6125..3865ca0ce04a 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -2290,13 +2290,17 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs) rc = cifs_set_file_size(inode, attrs, xid, full_path); if (rc != 0) goto out; } - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) - attrs->ia_valid &= ~ATTR_MODE; + /* + * This function is only called when Unix extensions are in effect, + * so the mode is always sent to and stored on the server. Do not + * skip the mode change when clearing setuid/setgid bits: dropping + * ATTR_MODE here would leave those bits set on the server after a + * write, which is a security issue. + */ args = kmalloc(sizeof(*args), GFP_KERNEL); if (args == NULL) { rc = -ENOMEM; goto out; @@ -2461,12 +2465,27 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs) } else #endif /* CONFIG_CIFS_ACL */ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) attrs->ia_valid &= ~(ATTR_UID | ATTR_GID); - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) + /* + * Skip the mode change if it is only being done to clear the + * setuid/setgid bits *and* the mode is emulated via the DOS + * read-only attribute (the default, non-ACL case), which cannot + * represent the setuid/setgid bits anyway. + * + * When the mode is instead stored on the server - i.e. with the + * cifsacl or modefromsid mount options (via an ACL) or with the + * SMB3.1.1 POSIX extensions - the cleared mode must be pushed to + * the server. Dropping ATTR_MODE here would leave the setuid/ + * setgid bit set on the server after a write, which is a security + * issue (the bits are not stripped as they are on local + * filesystems). + */ + if ((attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) && + !((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) || + cifs_sb_master_tcon(cifs_sb)->posix_extensions)) attrs->ia_valid &= ~ATTR_MODE; if (attrs->ia_valid & ATTR_MODE) { mode = attrs->ia_mode; rc = 0; -- 2.52.0

2 1

[PATCH openEuler-1.0-LTS] smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions
by Zizhi Wo 18 Sep '26

18 Sep '26

From: Jiangshan Yi <yijiangshan(a)kylinos.cn> stable inclusion from stable-v6.18.51 commit b10015807e4c628095d1d1d1c9307efc8cdd9e1b category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18923 CVE: CVE-2026-89638 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit… -------------------------------- [ Upstream commit b8e5dc4f95e5484159b343903f302eb6d783f2e6 ] When a file has the setuid or setgid bit set and is written to, the VFS strips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID together with an ATTR_MODE carrying the already-cleared mode. Both cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped ATTR_MODE in that case: /* skip mode change if it's just for clearing setuid/setgid */ if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) attrs->ia_valid &= ~ATTR_MODE; This is fine for the default mount, where the mode is only emulated via the DOS read-only attribute and cannot represent the setuid/setgid bits anyway. However, with the "cifsacl" or "modefromsid" mount options the mode is stored on the server through an ACL (id_mode_to_cifs_acl()), with the SMB3.1.1 POSIX extensions the mode is sent to the server directly, and with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent via CIFSSMBUnixSetPathInfo(). In all those cases dropping ATTR_MODE means the cleared mode is never pushed to the server, so the setuid/setgid bit survives the write. This is a security issue: on local filesystems the setuid bit is stripped when a file is written, but over these cifs.ko mounts the bit persists on the server, potentially allowing an unexpected privilege escalation on subsequent execution. Fix this in two places: 1. cifs_setattr_nounix(): only take the "skip mode change" shortcut when the mode is emulated via the DOS read-only attribute (i.e. neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are in effect), so that the cleared mode is propagated to the server in the ACL / POSIX cases. 2. cifs_setattr_unix(): this function is only called when Unix extensions are in effect, so the mode is always stored on the server. Remove the shortcut entirely so that the cleared mode is always pushed. Fixes: d32c4f2626ac ("CIFS: ignore mode change if it's just for clearing setuid/setgid bits") Cc: stable(a)vger.kernel.org Signed-off-by: Jiangshan Yi <yijiangshan(a)kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Paulo Alcantara <pc(a)manguebit.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Conflicts: fs/cifs/inode.c fs/smb/client/inode.c [1. Commit b8e5dc4f95e5 touches fs/smb/client/inode.c, which this tree still has as fs/cifs/inode.c. The new check used the upstream-local sbflags variable, which does not exist here, so use cifs_sb->mnt_cifs_flags instead. 2. Commit 412094a8fb07 ("smb3: add new mount option to retrieve mode from special ACE") introduce CIFS_MOUNT_MODE_FROM_SID, this version has not merged.] Signed-off-by: Zizhi Wo <wozizhi(a)huawei.com> Signed-off-by: Zizhi Wo <wozizhi(a)huawei.com> --- fs/cifs/inode.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index e5d0066f6125..3865ca0ce04a 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -2290,13 +2290,17 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs) rc = cifs_set_file_size(inode, attrs, xid, full_path); if (rc != 0) goto out; } - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) - attrs->ia_valid &= ~ATTR_MODE; + /* + * This function is only called when Unix extensions are in effect, + * so the mode is always sent to and stored on the server. Do not + * skip the mode change when clearing setuid/setgid bits: dropping + * ATTR_MODE here would leave those bits set on the server after a + * write, which is a security issue. + */ args = kmalloc(sizeof(*args), GFP_KERNEL); if (args == NULL) { rc = -ENOMEM; goto out; @@ -2461,12 +2465,27 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs) } else #endif /* CONFIG_CIFS_ACL */ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) attrs->ia_valid &= ~(ATTR_UID | ATTR_GID); - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) + /* + * Skip the mode change if it is only being done to clear the + * setuid/setgid bits *and* the mode is emulated via the DOS + * read-only attribute (the default, non-ACL case), which cannot + * represent the setuid/setgid bits anyway. + * + * When the mode is instead stored on the server - i.e. with the + * cifsacl or modefromsid mount options (via an ACL) or with the + * SMB3.1.1 POSIX extensions - the cleared mode must be pushed to + * the server. Dropping ATTR_MODE here would leave the setuid/ + * setgid bit set on the server after a write, which is a security + * issue (the bits are not stripped as they are on local + * filesystems). + */ + if ((attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) && + !((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) || + cifs_sb_master_tcon(cifs_sb)->posix_extensions)) attrs->ia_valid &= ~ATTR_MODE; if (attrs->ia_valid & ATTR_MODE) { mode = attrs->ia_mode; rc = 0; -- 2.52.0

2 1

[PATCH] smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions
by Zizhi Wo 18 Sep '26

18 Sep '26

From: Jiangshan Yi <yijiangshan(a)kylinos.cn> stable inclusion from stable-v6.18.51 commit b10015807e4c628095d1d1d1c9307efc8cdd9e1b category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18923 CVE: CVE-2026-89638 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit… -------------------------------- [ Upstream commit b8e5dc4f95e5484159b343903f302eb6d783f2e6 ] When a file has the setuid or setgid bit set and is written to, the VFS strips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID together with an ATTR_MODE carrying the already-cleared mode. Both cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped ATTR_MODE in that case: /* skip mode change if it's just for clearing setuid/setgid */ if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) attrs->ia_valid &= ~ATTR_MODE; This is fine for the default mount, where the mode is only emulated via the DOS read-only attribute and cannot represent the setuid/setgid bits anyway. However, with the "cifsacl" or "modefromsid" mount options the mode is stored on the server through an ACL (id_mode_to_cifs_acl()), with the SMB3.1.1 POSIX extensions the mode is sent to the server directly, and with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent via CIFSSMBUnixSetPathInfo(). In all those cases dropping ATTR_MODE means the cleared mode is never pushed to the server, so the setuid/setgid bit survives the write. This is a security issue: on local filesystems the setuid bit is stripped when a file is written, but over these cifs.ko mounts the bit persists on the server, potentially allowing an unexpected privilege escalation on subsequent execution. Fix this in two places: 1. cifs_setattr_nounix(): only take the "skip mode change" shortcut when the mode is emulated via the DOS read-only attribute (i.e. neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are in effect), so that the cleared mode is propagated to the server in the ACL / POSIX cases. 2. cifs_setattr_unix(): this function is only called when Unix extensions are in effect, so the mode is always stored on the server. Remove the shortcut entirely so that the cleared mode is always pushed. Fixes: d32c4f2626ac ("CIFS: ignore mode change if it's just for clearing setuid/setgid bits") Cc: stable(a)vger.kernel.org Signed-off-by: Jiangshan Yi <yijiangshan(a)kylinos.cn> Signed-off-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Paulo Alcantara <pc(a)manguebit.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Conflicts: fs/cifs/inode.c fs/smb/client/inode.c [Commit b8e5dc4f95e5 touches fs/smb/client/inode.c, which this tree still has as fs/cifs/inode.c. The new check used the upstream-local sbflags variable, which does not exist here, so use cifs_sb->mnt_cifs_flags instead.] Signed-off-by: Zizhi Wo <wozizhi(a)huawei.com> --- fs/cifs/inode.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 045d77a929df..83974a528024 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -2662,13 +2662,17 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs) rc = cifs_set_file_size(inode, attrs, xid, full_path); if (rc != 0) goto out; } - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) - attrs->ia_valid &= ~ATTR_MODE; + /* + * This function is only called when Unix extensions are in effect, + * so the mode is always sent to and stored on the server. Do not + * skip the mode change when clearing setuid/setgid bits: dropping + * ATTR_MODE here would leave those bits set on the server after a + * write, which is a security issue. + */ args = kmalloc(sizeof(*args), GFP_KERNEL); if (args == NULL) { rc = -ENOMEM; goto out; @@ -2848,12 +2852,28 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs) } } else if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) attrs->ia_valid &= ~(ATTR_UID | ATTR_GID); - /* skip mode change if it's just for clearing setuid/setgid */ - if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) + /* + * Skip the mode change if it is only being done to clear the + * setuid/setgid bits *and* the mode is emulated via the DOS + * read-only attribute (the default, non-ACL case), which cannot + * represent the setuid/setgid bits anyway. + * + * When the mode is instead stored on the server - i.e. with the + * cifsacl or modefromsid mount options (via an ACL) or with the + * SMB3.1.1 POSIX extensions - the cleared mode must be pushed to + * the server. Dropping ATTR_MODE here would leave the setuid/ + * setgid bit set on the server after a write, which is a security + * issue (the bits are not stripped as they are on local + * filesystems). + */ + if ((attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) && + !((cifs_sb->mnt_cifs_flags & + (CIFS_MOUNT_CIFS_ACL | CIFS_MOUNT_MODE_FROM_SID)) || + cifs_sb_master_tcon(cifs_sb)->posix_extensions)) attrs->ia_valid &= ~ATTR_MODE; if (attrs->ia_valid & ATTR_MODE) { mode = attrs->ia_mode; rc = 0; -- 2.52.0

1 0

[PATCH OLK-5.10] cifs: fix loff_t underflow in cifs_remap_file_range() when len == 0
by Zizhi Wo 18 Sep '26

18 Sep '26

From: Frank Sorenson <sorenson(a)redhat.com> mainline inclusion from mainline-v7.3-rc1 commit 6c322f5cf7476ded7a9a20f7be72462065a03c68 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18924 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- With len == 0 (clone to EOF), the effective length is computed as: len = src_inode->i_size - off; If off > i_size, this is a negative loff_t, corrupting the ByteCount in the FSCTL_DUPLICATE_EXTENTS_TO_FILE request and inverting the range in filemap_write_and_wait_range(). The existing off >= i_size check fires only after the ioctl has already been sent. Snapshot i_size_read() once for both the bounds check and the length calculation, eliminating the TOCTOU and 32-bit torn-read risk. Reject off > src_size with -EINVAL. Treat off == src_size as a no-op, consistent with __generic_remap_file_range_prep(). Fixes: 04b38d601239 ("vfs: pull btrfs clone API to vfs layer") Cc: stable(a)vger.kernel.org Signed-off-by: Frank Sorenson <sorenson(a)redhat.com> Reviewed-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Paulo Alcantara <pc(a)manguebit.org> Conflicts: fs/cifs/cifsfs.c [5.10 keeps this file at fs/cifs/cifsfs.c and its cifs_remap_file_range() has no unlock label, which this fix references; add unlock: right before unlock_two_nondirectories() so the new error and zero-length exits release the locks and still free the xid via the existing out: path.] Signed-off-by: Zizhi Wo <wozizhi(a)huawei.com> --- fs/cifs/cifsfs.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index a86a1fb34e59..1d102d8c3ba6 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -1116,12 +1116,23 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off, * checks for proper open modes and file type and if it wants * server could even support copy of range where source = target */ lock_two_nondirectories(target_inode, src_inode); - if (len == 0) - len = src_inode->i_size - off; + if (len == 0) { + loff_t src_size = i_size_read(src_inode); + + if (off > src_size) { + rc = -EINVAL; + goto unlock; + } + len = src_size - off; + if (!len) { + rc = 0; + goto unlock; + } + } cifs_dbg(FYI, "about to flush pages\n"); /* should we flush first and last page first */ truncate_inode_pages_range(&target_inode->i_data, destoff, PAGE_ALIGN(destoff + len)-1); @@ -1133,10 +1144,11 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off, rc = -EOPNOTSUPP; /* force revalidate of size and timestamps of target file now that target is updated on the server */ CIFS_I(target_inode)->time = 0; +unlock: /* although unlocking in the reverse order from locking is not strictly necessary here it is a little cleaner to be consistent */ unlock_two_nondirectories(src_inode, target_inode); out: free_xid(xid); -- 2.52.0

2 1

[PATCH OLK-6.6 0/5] mainline patch submission for OLK-6.6
by Chen Yuxi 18 Sep '26

18 Sep '26

Nicholas Dudar (2): bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max bpf: Reject writes through untrusted BTF pointers Pu Lehui (2): bpf: Fix potential UAF when reading bpf link info bpf: Fix potential UAF in bpf_netns_link_update_prog Sanghyun Park (1): bpf: Fix use-after-free on mm_struct in bpf_find_vma() kernel/bpf/net_namespace.c | 17 ++++++----------- kernel/bpf/syscall.c | 21 +++++++++++++++++---- kernel/bpf/task_iter.c | 36 +++++++++++++++++++++++++++++++++--- kernel/bpf/verifier.c | 13 +++++++++++-- 4 files changed, 67 insertions(+), 20 deletions(-) -- 2.34.1

2 6

[PATCH OLK-6.6 0/5] mainline patch submission for OLK-6.6
by Chen Yuxi 18 Sep '26

18 Sep '26

Nicholas Dudar (2): bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max bpf: Reject writes through untrusted BTF pointers Pu Lehui (2): bpf: Fix potential UAF when reading bpf link info bpf: Fix potential UAF in bpf_netns_link_update_prog Sanghyun Park (1): bpf: Fix use-after-free on mm_struct in bpf_find_vma() kernel/bpf/net_namespace.c | 17 ++++++----------- kernel/bpf/syscall.c | 21 +++++++++++++++++---- kernel/bpf/task_iter.c | 36 +++++++++++++++++++++++++++++++++--- kernel/bpf/verifier.c | 13 +++++++++++-- 4 files changed, 67 insertions(+), 20 deletions(-) -- 2.34.1

2 6