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Unrated severityNVD Advisory· Published May 27, 2026· Updated May 27, 2026

CVE-2026-45961

CVE-2026-45961

Description

In the Linux kernel, the following vulnerability has been resolved:

gfs2: fix memory leaks in gfs2_fill_super error path

Fix two memory leaks in the gfs2_fill_super() error handling path when transitioning a filesystem to read-write mode fails.

First leak: kthread objects (thread_struct, task_struct, etc.) When gfs2_freeze_lock_shared() fails after init_threads() succeeds, the created kernel threads (logd and quotad) are never destroyed. This occurs because the fail_per_node label doesn't call gfs2_destroy_threads().

Second leak: quota bitmap buffer (8192 bytes) When gfs2_make_fs_rw() fails after gfs2_quota_init() succeeds but before other operations complete, the allocated quota bitmap is never freed.

The fix moves thread cleanup to the fail_per_node label to handle all error paths uniformly. gfs2_destroy_threads() is safe to call unconditionally as it checks for NULL pointers. Quota cleanup is added in gfs2_make_fs_rw() to properly handle the withdrawal case where quota initialization succeeds but the filesystem is then withdrawn.

Thread leak backtrace (gfs2_freeze_lock_shared failure): unreferenced object 0xffff88801d7bca80 (size 4480): copy_process+0x3a1/0x4670 kernel/fork.c:2422 kernel_clone+0xf3/0x6e0 kernel/fork.c:2779 kthread_create_on_node+0x100/0x150 kernel/kthread.c:478 init_threads+0xab/0x350 fs/gfs2/ops_fstype.c:611 gfs2_fill_super+0xe5c/0x1240 fs/gfs2/ops_fstype.c:1265

Quota leak backtrace (gfs2_make_fs_rw failure): unreferenced object 0xffff88812de7c000 (size 8192): gfs2_quota_init+0xe5/0x820 fs/gfs2/quota.c:1409 gfs2_make_fs_rw+0x7a/0xe0 fs/gfs2/super.c:149 gfs2_fill_super+0xfbb/0x1240 fs/gfs2/ops_fstype.c:1275

Affected products

1

Patches

4
e54229ecf49a

gfs2: fix memory leaks in gfs2_fill_super error path

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.gitDeepanshu KartikeyFixed in 6.19.4via kernel-cna
commit
4 files changed · +8 −6
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg
da6f5bbc2e79

gfs2: fix memory leaks in gfs2_fill_super error path

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.gitDeepanshu KartikeyFixed in 7.0via kernel-cna
commit
4 files changed · +8 −6
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg
da6f5bbc2e79

gfs2: fix memory leaks in gfs2_fill_super error path

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.gitDeepanshu Kartikeyvia nvd-ref
commit
4 files changed · +8 −6
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg
e54229ecf49a

gfs2: fix memory leaks in gfs2_fill_super error path

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.gitDeepanshu Kartikeyvia nvd-ref
commit
4 files changed · +8 −6
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/ops_fstype.c+1 −1 modified
    diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e7a88b717991ae..c7d57de7c8f06b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1276,7 +1276,6 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	if (error) {
 		gfs2_freeze_unlock(sdp);
-		gfs2_destroy_threads(sdp);
 		fs_err(sdp, "can't make FS RW: %d\n", error);
 		goto fail_per_node;
 	}
@@ -1286,6 +1285,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
 
 fail_per_node:
 	init_per_node(sdp, UNDO);
+	gfs2_destroy_threads(sdp);
 fail_inodes:
 	init_inodes(sdp, UNDO);
 fail_sb:
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg
  • fs/gfs2/super.c+3 −2 modified
    diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index f6cd907b3ec6c4..d96160636161c8 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -147,8 +147,10 @@ int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	}
 
 	error = gfs2_quota_init(sdp);
-	if (!error && gfs2_withdrawn(sdp))
+	if (!error && gfs2_withdrawn(sdp)) {
+		gfs2_quota_cleanup(sdp);
 		error = -EIO;
+	}
 	if (!error)
 		set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 	return error;
-- 
cgit 1.3-korg

Vulnerability mechanics

Root cause

"Missing cleanup calls in error handling paths of gfs2_fill_super() and gfs2_make_fs_rw() cause kernel thread objects and quota bitmap buffers to be leaked when transitioning a filesystem to read-write mode fails."

Attack vector

An attacker with the ability to mount a GFS2 filesystem can trigger the error paths by causing gfs2_freeze_lock_shared() to fail after init_threads() has created kernel threads (logd and quotad), or by causing gfs2_make_fs_rw() to fail after gfs2_quota_init() allocates the quota bitmap. This results in unreferenced kthread objects (4480 bytes each) and an 8192-byte quota bitmap buffer that are never freed, leading to kernel memory exhaustion over repeated mount attempts. No special network access is required; the attack vector is local filesystem mount operations.

Affected code

The bugs are in fs/gfs2/ops_fstype.c in the gfs2_fill_super() function (around line 1276 and the fail_per_node label at line 1286) and in fs/gfs2/super.c in the gfs2_make_fs_rw() function (around line 149). In ops_fstype.c, gfs2_destroy_threads() was called only in one error branch before jumping to fail_per_node, but fail_per_node itself did not call it. In super.c, when gfs2_quota_init() succeeded but the filesystem was withdrawn, the quota bitmap was not freed.

What the fix does

The patch makes two changes. First, in fs/gfs2/ops_fstype.c, the call to gfs2_destroy_threads() is moved from the inline error path (after gfs2_freeze_unlock) to the fail_per_node label, ensuring threads are destroyed on all error paths that reach that label. Second, in fs/gfs2/super.c, when gfs2_quota_init() succeeds but the filesystem is found to be withdrawn, gfs2_quota_cleanup(sdp) is now called before returning -EIO, freeing the allocated quota bitmap. Both changes ensure that resources allocated during the read-write transition are properly released on failure.

Preconditions

  • authAttacker must have the ability to mount a GFS2 filesystem (requires local access or sufficient privileges).
  • inputThe filesystem must be configured such that the transition to read-write mode can fail after threads or quota have been initialized (e.g., gfs2_freeze_lock_shared failure or filesystem withdrawal).

Generated on May 27, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

2

News mentions

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