From: Max Kellermann <max.kellermann(a)ionos.com>
commit 550f7ca98ee028a606aa75705a7e77b1bd11720f upstream.
If the full path to be built by ceph_mdsc_build_path() happens to be
longer than PATH_MAX, then this function will enter an endless (retry)
loop, effectively blocking the whole task. Most of the machine
becomes unusable, making this a very simple and effective DoS
vulnerability.
I cannot imagine why this retry was ever implemented, but it seems
rather useless and harmful to me. Let's remove it and fail with
ENAMETOOLONG instead.
Cc: stable(a)vger.kernel.org
Reported-by: Dario Weißer <dario(a)cure53.de>
Signed-off-by: Max Kellermann <max.kellermann(a)ionos.com>
Reviewed-by: Alex Markuze <amarkuze(a)redhat.com>
Signed-off-by: Ilya Dryomov <idryomov(a)gmail.com>
[idryomov(a)gmail.com: backport to 6.6: pr_warn() is still in use]
---
fs/ceph/mds_client.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 11289ce8a8cc..dfa1b3c82b53 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2713,12 +2713,11 @@ char *ceph_mdsc_build_path(struct ceph_mds_client *mdsc, struct dentry *dentry,
if (pos < 0) {
/*
- * A rename didn't occur, but somehow we didn't end up where
- * we thought we would. Throw a warning and try again.
+ * The path is longer than PATH_MAX and this function
+ * cannot ever succeed. Creating paths that long is
+ * possible with Ceph, but Linux cannot use them.
*/
- pr_warn("build_path did not end path lookup where expected (pos = %d)\n",
- pos);
- goto retry;
+ return ERR_PTR(-ENAMETOOLONG);
}
*pbase = base;
--
2.46.1
The MT8173 disp-pwm device should have only one compatible string, based
on the following DT validation error:
arch/arm64/boot/dts/mediatek/mt8173-elm.dtb: pwm@1401e000: compatible: 'oneOf' conditional failed, one must be fixed:
['mediatek,mt8173-disp-pwm', 'mediatek,mt6595-disp-pwm'] is too long
'mediatek,mt8173-disp-pwm' is not one of ['mediatek,mt6795-disp-pwm', 'mediatek,mt8167-disp-pwm']
'mediatek,mt8173-disp-pwm' is not one of ['mediatek,mt8186-disp-pwm', 'mediatek,mt8188-disp-pwm', 'mediatek,mt8192-disp-pwm', 'mediatek,mt8195-disp-pwm', 'mediatek,mt8365-disp-pwm']
'mediatek,mt8173-disp-pwm' was expected
'mediatek,mt8183-disp-pwm' was expected
from schema $id: http://devicetree.org/schemas/pwm/mediatek,pwm-disp.yaml#
arch/arm64/boot/dts/mediatek/mt8173-elm.dtb: pwm@1401f000: compatible: 'oneOf' conditional failed, one must be fixed:
['mediatek,mt8173-disp-pwm', 'mediatek,mt6595-disp-pwm'] is too long
'mediatek,mt8173-disp-pwm' is not one of ['mediatek,mt6795-disp-pwm', 'mediatek,mt8167-disp-pwm']
'mediatek,mt8173-disp-pwm' is not one of ['mediatek,mt8186-disp-pwm', 'mediatek,mt8188-disp-pwm', 'mediatek,mt8192-disp-pwm', 'mediatek,mt8195-disp-pwm', 'mediatek,mt8365-disp-pwm']
'mediatek,mt8173-disp-pwm' was expected
'mediatek,mt8183-disp-pwm' was expected
from schema $id: http://devicetree.org/schemas/pwm/mediatek,pwm-disp.yaml#
Drop the extra "mediatek,mt6595-disp-pwm" compatible string.
Fixes: 61aee9342514 ("arm64: dts: mt8173: add MT8173 display PWM driver support node")
Cc: YH Huang <yh.huang(a)mediatek.com>
Cc: <stable(a)vger.kernel.org> # v4.5+
Signed-off-by: Chen-Yu Tsai <wenst(a)chromium.org>
---
arch/arm64/boot/dts/mediatek/mt8173.dtsi | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/boot/dts/mediatek/mt8173.dtsi b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
index 3458be7f7f61..f49ec7495906 100644
--- a/arch/arm64/boot/dts/mediatek/mt8173.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8173.dtsi
@@ -1255,8 +1255,7 @@ dpi0_out: endpoint {
};
pwm0: pwm@1401e000 {
- compatible = "mediatek,mt8173-disp-pwm",
- "mediatek,mt6595-disp-pwm";
+ compatible = "mediatek,mt8173-disp-pwm";
reg = <0 0x1401e000 0 0x1000>;
#pwm-cells = <2>;
clocks = <&mmsys CLK_MM_DISP_PWM026M>,
@@ -1266,8 +1265,7 @@ pwm0: pwm@1401e000 {
};
pwm1: pwm@1401f000 {
- compatible = "mediatek,mt8173-disp-pwm",
- "mediatek,mt6595-disp-pwm";
+ compatible = "mediatek,mt8173-disp-pwm";
reg = <0 0x1401f000 0 0x1000>;
#pwm-cells = <2>;
clocks = <&mmsys CLK_MM_DISP_PWM126M>,
--
2.47.1.613.gc27f4b7a9f-goog
The last two are perhaps not strictly fixes, as they essentially add
support for nested ATRs. The first one is a fix, thus stable is in cc.
Tomi
Signed-off-by: Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com>
---
Changes in v2:
- Use mutext_init_with_key()
- Rearrange the series so that the fix is the first patch
- Link to v1: https://lore.kernel.org/r/20241122-i2c-atr-fixes-v1-0-62c51ce790be@ideasonb…
---
Cosmin Tanislav (1):
i2c: atr: Allow unmapped addresses from nested ATRs
Tomi Valkeinen (2):
i2c: atr: Fix client detach
i2c: atr: Fix lockdep for nested ATRs
drivers/i2c/i2c-atr.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
---
base-commit: adc218676eef25575469234709c2d87185ca223a
change-id: 20241121-i2c-atr-fixes-6d52b9f5f0c1
Best regards,
--
Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com>
Since the backport commit eea46baf1451 ("ftrace: Fix possible
use-after-free issue in ftrace_location()") on linux-5.4.y branch, the
old ftrace_int3_handler()->ftrace_location() path has included
rcu_read_lock(), which has mcount location inside and leads to potential
double fault.
Replace rcu_read_lock/unlock with preempt_enable/disable notrace macros
so that the mcount location does not appear on the int3 handler path.
This fix is specific to linux-5.4.y branch, the only branch still using
ftrace_int3_handler with commit e60b613df8b6 ("ftrace: Fix possible
use-after-free issue in ftrace_location()") backported. It also avoids
the need to backport the code conversion to text_poke() on this branch.
Reported-by: Koichiro Den <koichiro.den(a)canonical.com>
Closes: https://lore.kernel.org/all/74gjhwxupvozwop7ndhrh7t5qeckomt7yqvkkbm5j2tlx6d…
Fixes: eea46baf1451 ("ftrace: Fix possible use-after-free issue in ftrace_location()") # linux-5.4.y
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
Signed-off-by: Koichiro Den <koichiro.den(a)canonical.com>
---
kernel/trace/ftrace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 380032a27f98..2eb1a8ec5755 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1554,7 +1554,7 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
struct dyn_ftrace key;
unsigned long ip = 0;
- rcu_read_lock();
+ preempt_disable_notrace();
key.ip = start;
key.flags = end; /* overload flags, as it is unsigned long */
@@ -1572,7 +1572,7 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
break;
}
}
- rcu_read_unlock();
+ preempt_enable_notrace();
return ip;
}
--
2.43.0