The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 2d9463083ce92636a1bdd3e30d1236e3e95d859e Mon Sep 17 00:00:00 2001
From: Anant Thazhemadam <anant.thazhemadam(a)gmail.com>
Date: Sat, 5 Dec 2020 03:28:25 +0530
Subject: [PATCH] nl80211: validate key indexes for cfg80211_registered_device
syzbot discovered a bug in which an OOB access was being made because
an unsuitable key_idx value was wrongly considered to be acceptable
while deleting a key in nl80211_del_key().
Since we don't know the cipher at the time of deletion, if
cfg80211_validate_key_settings() were to be called directly in
nl80211_del_key(), even valid keys would be wrongly determined invalid,
and deletion wouldn't occur correctly.
For this reason, a new function - cfg80211_valid_key_idx(), has been
created, to determine if the key_idx value provided is valid or not.
cfg80211_valid_key_idx() is directly called in 2 places -
nl80211_del_key(), and cfg80211_validate_key_settings().
Reported-by: syzbot+49d4cab497c2142ee170(a)syzkaller.appspotmail.com
Tested-by: syzbot+49d4cab497c2142ee170(a)syzkaller.appspotmail.com
Suggested-by: Johannes Berg <johannes(a)sipsolutions.net>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam(a)gmail.com>
Link: https://lore.kernel.org/r/20201204215825.129879-1-anant.thazhemadam@gmail.c…
Cc: stable(a)vger.kernel.org
[also disallow IGTK key IDs if no IGTK cipher is supported]
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
diff --git a/net/wireless/core.h b/net/wireless/core.h
index e3e9686859d4..7df91f940212 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -433,6 +433,8 @@ void cfg80211_sme_abandon_assoc(struct wireless_dev *wdev);
/* internal helpers */
bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher);
+bool cfg80211_valid_key_idx(struct cfg80211_registered_device *rdev,
+ int key_idx, bool pairwise);
int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
struct key_params *params, int key_idx,
bool pairwise, const u8 *mac_addr);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c8d31181a660..910872974f2d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4239,9 +4239,6 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
if (err)
return err;
- if (key.idx < 0)
- return -EINVAL;
-
if (info->attrs[NL80211_ATTR_MAC])
mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
@@ -4257,6 +4254,10 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
key.type != NL80211_KEYTYPE_GROUP)
return -EINVAL;
+ if (!cfg80211_valid_key_idx(rdev, key.idx,
+ key.type == NL80211_KEYTYPE_PAIRWISE))
+ return -EINVAL;
+
if (!rdev->ops->del_key)
return -EOPNOTSUPP;
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 79c5780e3033..b4acc805114b 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -272,18 +272,53 @@ bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher)
return false;
}
-int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
- struct key_params *params, int key_idx,
- bool pairwise, const u8 *mac_addr)
+static bool
+cfg80211_igtk_cipher_supported(struct cfg80211_registered_device *rdev)
{
- int max_key_idx = 5;
+ struct wiphy *wiphy = &rdev->wiphy;
+ int i;
+
+ for (i = 0; i < wiphy->n_cipher_suites; i++) {
+ switch (wiphy->cipher_suites[i]) {
+ case WLAN_CIPHER_SUITE_AES_CMAC:
+ case WLAN_CIPHER_SUITE_BIP_CMAC_256:
+ case WLAN_CIPHER_SUITE_BIP_GMAC_128:
+ case WLAN_CIPHER_SUITE_BIP_GMAC_256:
+ return true;
+ }
+ }
+
+ return false;
+}
- if (wiphy_ext_feature_isset(&rdev->wiphy,
- NL80211_EXT_FEATURE_BEACON_PROTECTION) ||
- wiphy_ext_feature_isset(&rdev->wiphy,
- NL80211_EXT_FEATURE_BEACON_PROTECTION_CLIENT))
+bool cfg80211_valid_key_idx(struct cfg80211_registered_device *rdev,
+ int key_idx, bool pairwise)
+{
+ int max_key_idx;
+
+ if (pairwise)
+ max_key_idx = 3;
+ else if (wiphy_ext_feature_isset(&rdev->wiphy,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION) ||
+ wiphy_ext_feature_isset(&rdev->wiphy,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION_CLIENT))
max_key_idx = 7;
+ else if (cfg80211_igtk_cipher_supported(rdev))
+ max_key_idx = 5;
+ else
+ max_key_idx = 3;
+
if (key_idx < 0 || key_idx > max_key_idx)
+ return false;
+
+ return true;
+}
+
+int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
+ struct key_params *params, int key_idx,
+ bool pairwise, const u8 *mac_addr)
+{
+ if (!cfg80211_valid_key_idx(rdev, key_idx, pairwise))
return -EINVAL;
if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 2d9463083ce92636a1bdd3e30d1236e3e95d859e Mon Sep 17 00:00:00 2001
From: Anant Thazhemadam <anant.thazhemadam(a)gmail.com>
Date: Sat, 5 Dec 2020 03:28:25 +0530
Subject: [PATCH] nl80211: validate key indexes for cfg80211_registered_device
syzbot discovered a bug in which an OOB access was being made because
an unsuitable key_idx value was wrongly considered to be acceptable
while deleting a key in nl80211_del_key().
Since we don't know the cipher at the time of deletion, if
cfg80211_validate_key_settings() were to be called directly in
nl80211_del_key(), even valid keys would be wrongly determined invalid,
and deletion wouldn't occur correctly.
For this reason, a new function - cfg80211_valid_key_idx(), has been
created, to determine if the key_idx value provided is valid or not.
cfg80211_valid_key_idx() is directly called in 2 places -
nl80211_del_key(), and cfg80211_validate_key_settings().
Reported-by: syzbot+49d4cab497c2142ee170(a)syzkaller.appspotmail.com
Tested-by: syzbot+49d4cab497c2142ee170(a)syzkaller.appspotmail.com
Suggested-by: Johannes Berg <johannes(a)sipsolutions.net>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam(a)gmail.com>
Link: https://lore.kernel.org/r/20201204215825.129879-1-anant.thazhemadam@gmail.c…
Cc: stable(a)vger.kernel.org
[also disallow IGTK key IDs if no IGTK cipher is supported]
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
diff --git a/net/wireless/core.h b/net/wireless/core.h
index e3e9686859d4..7df91f940212 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -433,6 +433,8 @@ void cfg80211_sme_abandon_assoc(struct wireless_dev *wdev);
/* internal helpers */
bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher);
+bool cfg80211_valid_key_idx(struct cfg80211_registered_device *rdev,
+ int key_idx, bool pairwise);
int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
struct key_params *params, int key_idx,
bool pairwise, const u8 *mac_addr);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c8d31181a660..910872974f2d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4239,9 +4239,6 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
if (err)
return err;
- if (key.idx < 0)
- return -EINVAL;
-
if (info->attrs[NL80211_ATTR_MAC])
mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
@@ -4257,6 +4254,10 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
key.type != NL80211_KEYTYPE_GROUP)
return -EINVAL;
+ if (!cfg80211_valid_key_idx(rdev, key.idx,
+ key.type == NL80211_KEYTYPE_PAIRWISE))
+ return -EINVAL;
+
if (!rdev->ops->del_key)
return -EOPNOTSUPP;
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 79c5780e3033..b4acc805114b 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -272,18 +272,53 @@ bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher)
return false;
}
-int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
- struct key_params *params, int key_idx,
- bool pairwise, const u8 *mac_addr)
+static bool
+cfg80211_igtk_cipher_supported(struct cfg80211_registered_device *rdev)
{
- int max_key_idx = 5;
+ struct wiphy *wiphy = &rdev->wiphy;
+ int i;
+
+ for (i = 0; i < wiphy->n_cipher_suites; i++) {
+ switch (wiphy->cipher_suites[i]) {
+ case WLAN_CIPHER_SUITE_AES_CMAC:
+ case WLAN_CIPHER_SUITE_BIP_CMAC_256:
+ case WLAN_CIPHER_SUITE_BIP_GMAC_128:
+ case WLAN_CIPHER_SUITE_BIP_GMAC_256:
+ return true;
+ }
+ }
+
+ return false;
+}
- if (wiphy_ext_feature_isset(&rdev->wiphy,
- NL80211_EXT_FEATURE_BEACON_PROTECTION) ||
- wiphy_ext_feature_isset(&rdev->wiphy,
- NL80211_EXT_FEATURE_BEACON_PROTECTION_CLIENT))
+bool cfg80211_valid_key_idx(struct cfg80211_registered_device *rdev,
+ int key_idx, bool pairwise)
+{
+ int max_key_idx;
+
+ if (pairwise)
+ max_key_idx = 3;
+ else if (wiphy_ext_feature_isset(&rdev->wiphy,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION) ||
+ wiphy_ext_feature_isset(&rdev->wiphy,
+ NL80211_EXT_FEATURE_BEACON_PROTECTION_CLIENT))
max_key_idx = 7;
+ else if (cfg80211_igtk_cipher_supported(rdev))
+ max_key_idx = 5;
+ else
+ max_key_idx = 3;
+
if (key_idx < 0 || key_idx > max_key_idx)
+ return false;
+
+ return true;
+}
+
+int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
+ struct key_params *params, int key_idx,
+ bool pairwise, const u8 *mac_addr)
+{
+ if (!cfg80211_valid_key_idx(rdev, key_idx, pairwise))
return -EINVAL;
if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f7e0e8b2f1b0a09b527885babda3e912ba820798 Mon Sep 17 00:00:00 2001
From: Peilin Ye <yepeilin.cs(a)gmail.com>
Date: Wed, 9 Sep 2020 03:17:00 -0400
Subject: [PATCH] Bluetooth: Fix slab-out-of-bounds read in
hci_le_direct_adv_report_evt()
`num_reports` is not being properly checked. A malformed event packet with
a large `num_reports` number makes hci_le_direct_adv_report_evt() read out
of bounds. Fix it.
Cc: stable(a)vger.kernel.org
Fixes: 2f010b55884e ("Bluetooth: Add support for handling LE Direct Advertising Report events")
Reported-and-tested-by: syzbot+24ebd650e20bd263ca01(a)syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=24ebd650e20bd263ca01
Signed-off-by: Peilin Ye <yepeilin.cs(a)gmail.com>
Signed-off-by: Marcel Holtmann <marcel(a)holtmann.org>
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index e72982b69f6b..17a72695865b 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5873,21 +5873,19 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev,
struct sk_buff *skb)
{
u8 num_reports = skb->data[0];
- void *ptr = &skb->data[1];
+ struct hci_ev_le_direct_adv_info *ev = (void *)&skb->data[1];
- hci_dev_lock(hdev);
+ if (!num_reports || skb->len < num_reports * sizeof(*ev) + 1)
+ return;
- while (num_reports--) {
- struct hci_ev_le_direct_adv_info *ev = ptr;
+ hci_dev_lock(hdev);
+ for (; num_reports; num_reports--, ev++)
process_adv_report(hdev, ev->evt_type, &ev->bdaddr,
ev->bdaddr_type, &ev->direct_addr,
ev->direct_addr_type, ev->rssi, NULL, 0,
false);
- ptr += sizeof(*ev);
- }
-
hci_dev_unlock(hdev);
}
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f7e0e8b2f1b0a09b527885babda3e912ba820798 Mon Sep 17 00:00:00 2001
From: Peilin Ye <yepeilin.cs(a)gmail.com>
Date: Wed, 9 Sep 2020 03:17:00 -0400
Subject: [PATCH] Bluetooth: Fix slab-out-of-bounds read in
hci_le_direct_adv_report_evt()
`num_reports` is not being properly checked. A malformed event packet with
a large `num_reports` number makes hci_le_direct_adv_report_evt() read out
of bounds. Fix it.
Cc: stable(a)vger.kernel.org
Fixes: 2f010b55884e ("Bluetooth: Add support for handling LE Direct Advertising Report events")
Reported-and-tested-by: syzbot+24ebd650e20bd263ca01(a)syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=24ebd650e20bd263ca01
Signed-off-by: Peilin Ye <yepeilin.cs(a)gmail.com>
Signed-off-by: Marcel Holtmann <marcel(a)holtmann.org>
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index e72982b69f6b..17a72695865b 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5873,21 +5873,19 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev,
struct sk_buff *skb)
{
u8 num_reports = skb->data[0];
- void *ptr = &skb->data[1];
+ struct hci_ev_le_direct_adv_info *ev = (void *)&skb->data[1];
- hci_dev_lock(hdev);
+ if (!num_reports || skb->len < num_reports * sizeof(*ev) + 1)
+ return;
- while (num_reports--) {
- struct hci_ev_le_direct_adv_info *ev = ptr;
+ hci_dev_lock(hdev);
+ for (; num_reports; num_reports--, ev++)
process_adv_report(hdev, ev->evt_type, &ev->bdaddr,
ev->bdaddr_type, &ev->direct_addr,
ev->direct_addr_type, ev->rssi, NULL, 0,
false);
- ptr += sizeof(*ev);
- }
-
hci_dev_unlock(hdev);
}
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From bfc2b7e8518999003a61f91c1deb5e88ed77b07d Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers(a)google.com>
Date: Tue, 17 Nov 2020 23:56:07 -0800
Subject: [PATCH] f2fs: prevent creating duplicate encrypted filenames
As described in "fscrypt: add fscrypt_is_nokey_name()", it's possible to
create a duplicate filename in an encrypted directory by creating a file
concurrently with adding the directory's encryption key.
Fix this bug on f2fs by rejecting no-key dentries in f2fs_add_link().
Note that the weird check for the current task in f2fs_do_add_link()
seems to make this bug difficult to reproduce on f2fs.
Fixes: 9ea97163c6da ("f2fs crypto: add filename encryption for f2fs_add_link")
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20201118075609.120337-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index cb700d797296..9a321c52face 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3251,6 +3251,8 @@ bool f2fs_empty_dir(struct inode *dir);
static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
{
+ if (fscrypt_is_nokey_name(dentry))
+ return -ENOKEY;
return f2fs_do_add_link(d_inode(dentry->d_parent), &dentry->d_name,
inode, inode->i_ino, inode->i_mode);
}
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 75d18cd1868c2aee43553723872c35d7908f240f Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers(a)google.com>
Date: Tue, 17 Nov 2020 23:56:06 -0800
Subject: [PATCH] ext4: prevent creating duplicate encrypted filenames
As described in "fscrypt: add fscrypt_is_nokey_name()", it's possible to
create a duplicate filename in an encrypted directory by creating a file
concurrently with adding the directory's encryption key.
Fix this bug on ext4 by rejecting no-key dentries in ext4_add_entry().
Note that the duplicate check in ext4_find_dest_de() sometimes prevented
this bug. However in many cases it didn't, since ext4_find_dest_de()
doesn't examine every dentry.
Fixes: 4461471107b7 ("ext4 crypto: enable filename encryption")
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20201118075609.120337-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 33509266f5a0..793fc7db9d28 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2195,6 +2195,9 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
if (!dentry->d_name.len)
return -EINVAL;
+ if (fscrypt_is_nokey_name(dentry))
+ return -ENOKEY;
+
#ifdef CONFIG_UNICODE
if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 75d18cd1868c2aee43553723872c35d7908f240f Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers(a)google.com>
Date: Tue, 17 Nov 2020 23:56:06 -0800
Subject: [PATCH] ext4: prevent creating duplicate encrypted filenames
As described in "fscrypt: add fscrypt_is_nokey_name()", it's possible to
create a duplicate filename in an encrypted directory by creating a file
concurrently with adding the directory's encryption key.
Fix this bug on ext4 by rejecting no-key dentries in ext4_add_entry().
Note that the duplicate check in ext4_find_dest_de() sometimes prevented
this bug. However in many cases it didn't, since ext4_find_dest_de()
doesn't examine every dentry.
Fixes: 4461471107b7 ("ext4 crypto: enable filename encryption")
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20201118075609.120337-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 33509266f5a0..793fc7db9d28 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2195,6 +2195,9 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
if (!dentry->d_name.len)
return -EINVAL;
+ if (fscrypt_is_nokey_name(dentry))
+ return -ENOKEY;
+
#ifdef CONFIG_UNICODE
if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 75d18cd1868c2aee43553723872c35d7908f240f Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers(a)google.com>
Date: Tue, 17 Nov 2020 23:56:06 -0800
Subject: [PATCH] ext4: prevent creating duplicate encrypted filenames
As described in "fscrypt: add fscrypt_is_nokey_name()", it's possible to
create a duplicate filename in an encrypted directory by creating a file
concurrently with adding the directory's encryption key.
Fix this bug on ext4 by rejecting no-key dentries in ext4_add_entry().
Note that the duplicate check in ext4_find_dest_de() sometimes prevented
this bug. However in many cases it didn't, since ext4_find_dest_de()
doesn't examine every dentry.
Fixes: 4461471107b7 ("ext4 crypto: enable filename encryption")
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20201118075609.120337-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 33509266f5a0..793fc7db9d28 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2195,6 +2195,9 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
if (!dentry->d_name.len)
return -EINVAL;
+ if (fscrypt_is_nokey_name(dentry))
+ return -ENOKEY;
+
#ifdef CONFIG_UNICODE
if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 75d18cd1868c2aee43553723872c35d7908f240f Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers(a)google.com>
Date: Tue, 17 Nov 2020 23:56:06 -0800
Subject: [PATCH] ext4: prevent creating duplicate encrypted filenames
As described in "fscrypt: add fscrypt_is_nokey_name()", it's possible to
create a duplicate filename in an encrypted directory by creating a file
concurrently with adding the directory's encryption key.
Fix this bug on ext4 by rejecting no-key dentries in ext4_add_entry().
Note that the duplicate check in ext4_find_dest_de() sometimes prevented
this bug. However in many cases it didn't, since ext4_find_dest_de()
doesn't examine every dentry.
Fixes: 4461471107b7 ("ext4 crypto: enable filename encryption")
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20201118075609.120337-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 33509266f5a0..793fc7db9d28 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2195,6 +2195,9 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
if (!dentry->d_name.len)
return -EINVAL;
+ if (fscrypt_is_nokey_name(dentry))
+ return -ENOKEY;
+
#ifdef CONFIG_UNICODE
if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))