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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 5b4b2dcace35f618fe361a87bae6f0d13af31bc1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100756-clerk-lark-eecf@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
5b4b2dcace35 ("ext4: update orig_path in ext4_find_extent()")
c26ab35702f8 ("ext4: fix slab-use-after-free in ext4_split_extent_at()")
082cd4ec240b ("ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 5b4b2dcace35f618fe361a87bae6f0d13af31bc1 Mon Sep 17 00:00:00 2001
From: Baokun Li <libaokun1(a)huawei.com>
Date: Thu, 22 Aug 2024 10:35:25 +0800
Subject: [PATCH] ext4: update orig_path in ext4_find_extent()
In ext4_find_extent(), if the path is not big enough, we free it and set
*orig_path to NULL. But after reallocating and successfully initializing
the path, we don't update *orig_path, in which case the caller gets a
valid path but a NULL ppath, and this may cause a NULL pointer dereference
or a path memory leak. For example:
ext4_split_extent
path = *ppath = 2000
ext4_find_extent
if (depth > path[0].p_maxdepth)
kfree(path = 2000);
*orig_path = path = NULL;
path = kcalloc() = 3000
ext4_split_extent_at(*ppath = NULL)
path = *ppath;
ex = path[depth].p_ext;
// NULL pointer dereference!
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000010
CPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847
RIP: 0010:ext4_split_extent_at+0x6d/0x560
Call Trace:
<TASK>
ext4_split_extent.isra.0+0xcb/0x1b0
ext4_ext_convert_to_initialized+0x168/0x6c0
ext4_ext_handle_unwritten_extents+0x325/0x4d0
ext4_ext_map_blocks+0x520/0xdb0
ext4_map_blocks+0x2b0/0x690
ext4_iomap_begin+0x20e/0x2c0
[...]
==================================================================
Therefore, *orig_path is updated when the extent lookup succeeds, so that
the caller can safely use path or *ppath.
Fixes: 10809df84a4d ("ext4: teach ext4_ext_find_extent() to realloc path if necessary")
Cc: stable(a)kernel.org
Signed-off-by: Baokun Li <libaokun1(a)huawei.com>
Reviewed-by: Jan Kara <jack(a)suse.cz>
Link: https://patch.msgid.link/20240822023545.1994557-6-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index caef91356557..c8e7676f6af9 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -957,6 +957,8 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
ext4_ext_show_path(inode, path);
+ if (orig_path)
+ *orig_path = path;
return path;
err:
@@ -3268,7 +3270,6 @@ static int ext4_split_extent_at(handle_t *handle,
}
depth = ext_depth(inode);
ex = path[depth].p_ext;
- *ppath = path;
if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 516897b0218e..228b56f7d047 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -36,7 +36,6 @@ get_ext_path(struct inode *inode, ext4_lblk_t lblock,
*ppath = NULL;
return -ENODATA;
}
- *ppath = path;
return 0;
}
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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x c26ab35702f8cd0cdc78f96aa5856bfb77be798f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100730-plural-bobble-031b@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
c26ab35702f8 ("ext4: fix slab-use-after-free in ext4_split_extent_at()")
082cd4ec240b ("ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c26ab35702f8cd0cdc78f96aa5856bfb77be798f Mon Sep 17 00:00:00 2001
From: Baokun Li <libaokun1(a)huawei.com>
Date: Thu, 22 Aug 2024 10:35:23 +0800
Subject: [PATCH] ext4: fix slab-use-after-free in ext4_split_extent_at()
We hit the following use-after-free:
==================================================================
BUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0
Read of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40
CPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724
Call Trace:
<TASK>
kasan_report+0x93/0xc0
ext4_split_extent_at+0xba8/0xcc0
ext4_split_extent.isra.0+0x18f/0x500
ext4_split_convert_extents+0x275/0x750
ext4_ext_handle_unwritten_extents+0x73e/0x1580
ext4_ext_map_blocks+0xe20/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
Allocated by task 40:
__kmalloc_noprof+0x1ac/0x480
ext4_find_extent+0xf3b/0x1e70
ext4_ext_map_blocks+0x188/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
Freed by task 40:
kfree+0xf1/0x2b0
ext4_find_extent+0xa71/0x1e70
ext4_ext_insert_extent+0xa22/0x3260
ext4_split_extent_at+0x3ef/0xcc0
ext4_split_extent.isra.0+0x18f/0x500
ext4_split_convert_extents+0x275/0x750
ext4_ext_handle_unwritten_extents+0x73e/0x1580
ext4_ext_map_blocks+0xe20/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
==================================================================
The flow of issue triggering is as follows:
ext4_split_extent_at
path = *ppath
ext4_ext_insert_extent(ppath)
ext4_ext_create_new_leaf(ppath)
ext4_find_extent(orig_path)
path = *orig_path
read_extent_tree_block
// return -ENOMEM or -EIO
ext4_free_ext_path(path)
kfree(path)
*orig_path = NULL
a. If err is -ENOMEM:
ext4_ext_dirty(path + path->p_depth)
// path use-after-free !!!
b. If err is -EIO and we have EXT_DEBUG defined:
ext4_ext_show_leaf(path)
eh = path[depth].p_hdr
// path also use-after-free !!!
So when trying to zeroout or fix the extent length, call ext4_find_extent()
to update the path.
In addition we use *ppath directly as an ext4_ext_show_leaf() input to
avoid possible use-after-free when EXT_DEBUG is defined, and to avoid
unnecessary path updates.
Fixes: dfe5080939ea ("ext4: drop EXT4_EX_NOFREE_ON_ERR from rest of extents handling code")
Cc: stable(a)kernel.org
Signed-off-by: Baokun Li <libaokun1(a)huawei.com>
Reviewed-by: Jan Kara <jack(a)suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin(a)linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin(a)linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-4-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 4395e2b668ec..fe6bca63f9d6 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3251,6 +3251,25 @@ static int ext4_split_extent_at(handle_t *handle,
if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
goto out;
+ /*
+ * Update path is required because previous ext4_ext_insert_extent()
+ * may have freed or reallocated the path. Using EXT4_EX_NOFAIL
+ * guarantees that ext4_find_extent() will not return -ENOMEM,
+ * otherwise -ENOMEM will cause a retry in do_writepages(), and a
+ * WARN_ON may be triggered in ext4_da_update_reserve_space() due to
+ * an incorrect ee_len causing the i_reserved_data_blocks exception.
+ */
+ path = ext4_find_extent(inode, ee_block, ppath,
+ flags | EXT4_EX_NOFAIL);
+ if (IS_ERR(path)) {
+ EXT4_ERROR_INODE(inode, "Failed split extent on %u, err %ld",
+ split, PTR_ERR(path));
+ return PTR_ERR(path);
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ *ppath = path;
+
if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
if (split_flag & EXT4_EXT_DATA_VALID1) {
@@ -3303,7 +3322,7 @@ static int ext4_split_extent_at(handle_t *handle,
ext4_ext_dirty(handle, inode, path + path->p_depth);
return err;
out:
- ext4_ext_show_leaf(inode, path);
+ ext4_ext_show_leaf(inode, *ppath);
return err;
}
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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 5b4b2dcace35f618fe361a87bae6f0d13af31bc1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100721-bouncy-retreat-a211@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
5b4b2dcace35 ("ext4: update orig_path in ext4_find_extent()")
c26ab35702f8 ("ext4: fix slab-use-after-free in ext4_split_extent_at()")
082cd4ec240b ("ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 5b4b2dcace35f618fe361a87bae6f0d13af31bc1 Mon Sep 17 00:00:00 2001
From: Baokun Li <libaokun1(a)huawei.com>
Date: Thu, 22 Aug 2024 10:35:25 +0800
Subject: [PATCH] ext4: update orig_path in ext4_find_extent()
In ext4_find_extent(), if the path is not big enough, we free it and set
*orig_path to NULL. But after reallocating and successfully initializing
the path, we don't update *orig_path, in which case the caller gets a
valid path but a NULL ppath, and this may cause a NULL pointer dereference
or a path memory leak. For example:
ext4_split_extent
path = *ppath = 2000
ext4_find_extent
if (depth > path[0].p_maxdepth)
kfree(path = 2000);
*orig_path = path = NULL;
path = kcalloc() = 3000
ext4_split_extent_at(*ppath = NULL)
path = *ppath;
ex = path[depth].p_ext;
// NULL pointer dereference!
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000010
CPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847
RIP: 0010:ext4_split_extent_at+0x6d/0x560
Call Trace:
<TASK>
ext4_split_extent.isra.0+0xcb/0x1b0
ext4_ext_convert_to_initialized+0x168/0x6c0
ext4_ext_handle_unwritten_extents+0x325/0x4d0
ext4_ext_map_blocks+0x520/0xdb0
ext4_map_blocks+0x2b0/0x690
ext4_iomap_begin+0x20e/0x2c0
[...]
==================================================================
Therefore, *orig_path is updated when the extent lookup succeeds, so that
the caller can safely use path or *ppath.
Fixes: 10809df84a4d ("ext4: teach ext4_ext_find_extent() to realloc path if necessary")
Cc: stable(a)kernel.org
Signed-off-by: Baokun Li <libaokun1(a)huawei.com>
Reviewed-by: Jan Kara <jack(a)suse.cz>
Link: https://patch.msgid.link/20240822023545.1994557-6-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index caef91356557..c8e7676f6af9 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -957,6 +957,8 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
ext4_ext_show_path(inode, path);
+ if (orig_path)
+ *orig_path = path;
return path;
err:
@@ -3268,7 +3270,6 @@ static int ext4_split_extent_at(handle_t *handle,
}
depth = ext_depth(inode);
ex = path[depth].p_ext;
- *ppath = path;
if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 516897b0218e..228b56f7d047 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -36,7 +36,6 @@ get_ext_path(struct inode *inode, ext4_lblk_t lblock,
*ppath = NULL;
return -ENODATA;
}
- *ppath = path;
return 0;
}
This series is a v4.19 only backport (based on v4.19.322) of the recent
MIDR updates for the speculative SSBS workaround, which were originally
posted at:
https://lore.kernel.org/linux-arm-kernel/20240930111705.3352047-1-mark.rutl…
... and were originally merged upstream in v6.12-rc2.
The Cortex-A715 cputype definitions (which were originally merged
upstream in v6.2) are backported as a prerequisite.
Mark.
Anshuman Khandual (1):
arm64: Add Cortex-715 CPU part definition
Mark Rutland (2):
arm64: cputype: Add Neoverse-N3 definitions
arm64: errata: Expand speculative SSBS workaround once more
Documentation/arm64/silicon-errata.txt | 2 ++
arch/arm64/Kconfig | 2 ++
arch/arm64/include/asm/cputype.h | 4 ++++
arch/arm64/kernel/cpu_errata.c | 2 ++
4 files changed, 10 insertions(+)
--
2.30.2
This series is a v5.4 only backport (based on v5.4.284) of the recent
MIDR updates for the speculative SSBS workaround, which were originally
posted at:
https://lore.kernel.org/linux-arm-kernel/20240930111705.3352047-1-mark.rutl…
... and were originally merged upstream in v6.12-rc2.
The Cortex-A715 cputype definitions (which were originally merged
upstream in v6.2) are backported as a prerequisite.
This series does not apply to earlier stable trees, which will receive a
separate backport.
Mark.
Anshuman Khandual (1):
arm64: Add Cortex-715 CPU part definition
Mark Rutland (2):
arm64: cputype: Add Neoverse-N3 definitions
arm64: errata: Expand speculative SSBS workaround once more
Documentation/arm64/silicon-errata.rst | 4 ++++
arch/arm64/Kconfig | 2 ++
arch/arm64/include/asm/cputype.h | 4 ++++
arch/arm64/kernel/cpu_errata.c | 2 ++
4 files changed, 12 insertions(+)
--
2.30.2
This series is a v5.10.y only backport (based on v5.10.226) of the
recent MIDR updates for the speculative SSBS workaround, which were
originally posted at:
https://lore.kernel.org/linux-arm-kernel/20240930111705.3352047-1-mark.rutl…
... and were originally merged upstream in v6.12-rc2.
The Cortex-A715 cputype definitions (which were originally merged
upstream in v6.2) are backported as a prerequisite.
This series does not apply to earlier stable trees, which will receive a
separate backport.
Mark.
Anshuman Khandual (1):
arm64: Add Cortex-715 CPU part definition
Mark Rutland (2):
arm64: cputype: Add Neoverse-N3 definitions
arm64: errata: Expand speculative SSBS workaround once more
Documentation/arm64/silicon-errata.rst | 4 ++++
arch/arm64/Kconfig | 2 ++
arch/arm64/include/asm/cputype.h | 4 ++++
arch/arm64/kernel/cpu_errata.c | 2 ++
4 files changed, 12 insertions(+)
--
2.30.2
This series is a v5.15.y only backport (based on v5.15.167) of the
recent MIDR updates for the speculative SSBS workaround, which were
originally posted at:
https://lore.kernel.org/linux-arm-kernel/20240930111705.3352047-1-mark.rutl…
... and were originally merged upstream in v6.12-rc2.
The Cortex-A715 cputype definitions (which were originally merged
upstream in v6.2) are backported as a prerequisite.
This series does not apply to earlier stable trees, which will receive a
separate backport.
Mark.
Anshuman Khandual (1):
arm64: Add Cortex-715 CPU part definition
Mark Rutland (2):
arm64: cputype: Add Neoverse-N3 definitions
arm64: errata: Expand speculative SSBS workaround once more
Documentation/arm64/silicon-errata.rst | 4 ++++
arch/arm64/Kconfig | 2 ++
arch/arm64/include/asm/cputype.h | 4 ++++
arch/arm64/kernel/cpu_errata.c | 2 ++
4 files changed, 12 insertions(+)
--
2.30.2
This series is a v6.1 only backport (based on v6.1.112) of the recent MIDR
updates for the speculative SSBS workaround, which were originally posted at:
https://lore.kernel.org/linux-arm-kernel/20240930111705.3352047-1-mark.rutl…
... and were originally merged upstream in v6.12-rc2.
The Cortex-A715 cputype definitions (which were originally merged
upstream in v6.2) are backported as a prerequisite.
This series does not apply to earlier stable trees, which will receive a
separate backport.
Mark.
Anshuman Khandual (1):
arm64: Add Cortex-715 CPU part definition
Mark Rutland (2):
arm64: cputype: Add Neoverse-N3 definitions
arm64: errata: Expand speculative SSBS workaround once more
Documentation/arm64/silicon-errata.rst | 4 ++++
arch/arm64/Kconfig | 2 ++
arch/arm64/include/asm/cputype.h | 4 ++++
arch/arm64/kernel/cpu_errata.c | 2 ++
4 files changed, 12 insertions(+)
--
2.30.2
This series is a v6.6.y only backport (based on v6.6.54) of the recent
MIDR updates for the speculative SSBS workaround, which were originally
posted at:
https://lore.kernel.org/linux-arm-kernel/20240930111705.3352047-1-mark.rutl…https://lore.kernel.org/linux-arm-kernel/20241003225239.321774-1-eahariha@l…
... and were originally merged upstream in v6.12-rc2.
This series does not apply to earlier stable trees, which will receive a
separate backport.
Mark.
Easwar Hariharan (1):
arm64: Subscribe Microsoft Azure Cobalt 100 to erratum 3194386
Mark Rutland (2):
arm64: cputype: Add Neoverse-N3 definitions
arm64: errata: Expand speculative SSBS workaround once more
Documentation/arch/arm64/silicon-errata.rst | 6 ++++++
arch/arm64/Kconfig | 2 ++
arch/arm64/include/asm/cputype.h | 2 ++
arch/arm64/kernel/cpu_errata.c | 3 +++
4 files changed, 13 insertions(+)
--
2.30.2